1. ------IND- 2012 0320 D-- EN- ------ 20120611 --- --- PROJET
DEUTSCHER AUSSCHUSS FÜR
(GERMAN
COMMITTEE
FOR
CONCRETE)
STAHLBETON
REINFORCED
DafStb Guideline
Available from Beuth Verlag GmbH, Berlin, sales number 650XX
On the reinforcement of concrete parts
with adhesive bonding
Part 1: Design and construction
Draft March 2012
The requirements of Directive 98/34/EC of the European Parliament and of the Council of 22 June
1998 laying down a procedure for the provision of information in the field of technical standards and
regulations and of rules on Information Society services (OJ L 204 of 21 July 1998, p. 37), recently
amended by Directive 2006/96/EC (OJ L 363 of 20 December 2006, p. 81) have been taken into
account.
Regarding the standards, other documents and technical specifications related to products or test
procedures named in this Guideline, the rule is that other products and test procedures may be
applied if they meet the standards and other provisions and/or technical specifications of other EU
Member States, Turkey or other EFTA State, that is a Contract State of the European Economic
Area (EEA), provided the specified level of protection with regard to safety, health and suitability of
use is equally permanently achieved.
Published by:
Deutscher Ausschuss für Stahlbeton e. V. – DAfStb.
Budapester Straße 31
D – 10787 Berlin-Tiergarten
Phone: 030 2693-1320
info@dafstb.de
The Deutsche Ausschuss für Stahlbeton (DAfStb) retains all rights, including translation into foreign languages. This document or
any part thereof may not be photocopied or otherwise reproduced without the explicit permission of DAfStb.
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Foreword
(RV 1) This Guideline regulates the planning, design and execution of the reinforcement of
reinforced concrete and prestressed concrete components with fibre composite materials which are
bonded on or into indent cuts and bonded steel tabs.
(RV 2) The reinforcements to be bonded to the component surface to enhance shear strength
include commercial carbon fibre plates, carbon fibre sheeting and flat steel sections. Commercial
carbon fibre plates with special geometric requirements can also be glued into indent cuts in the
component.
(RV 3) The structure of this Guideline is based on DIN EN 1992-1-1. Unless stated otherwise, the
respective sections of DIN EN 1992-1-1 and its National Annex shall apply.
(RV 4) Requirements and information on product and system approvals are contained in Part 2 of
this Guideline.
(RV 5) Part 3 of this Guideline includes information on execution.
(RV 6) Part 4 of this Guideline contains supplemental rules on the Repair Guideline with regard to
planning of reinforcement measures.
(RV 7) The prefix RV in this Guideline indicates additional chapters, sections, paragraphs, figures,
tables and equations to DIN EN 1992-1-1 and the National Annex.
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Contents List Part 1
1General ........................................................................................................................... 9
1.1Scope ........................................................................................................................... 9
1.1.1 Scope of Eurocode 2 ............................................................................................................... 9
1.1.2 Scope of Part 1-1 of Eurocode 2 ............................................................................................. 9
RV 1.1.3 Scope of DAfStb Guideline Reinforcement of concrete parts with adhesive bonding ..... 9
1.2 Normative references ................................................................................................. 9
1.2.1 General reference standards .................................................................................................. 9
1.2.2 Other reference standards ...................................................................................................... 9
1.3 Assumptions .............................................................................................................. 9
1.4 Distinctions between principles and application rules...........................................10
1.5Definitions...................................................................................................................10
1.5.1General ................................................................................................................................... 10
1.5.2 Additional terms and definitions used in this Standard ......................................................... 10
1.6 Symbols .....................................................................................................................10
2 Basis of design ............................................................................................................. 16
2.1 Requirements ............................................................................................................16
2.1.1 Basic requirements ............................................................................................................... 16
2.1.2 Reliability management ......................................................................................................... 16
2.1.3 Design working life, durability and quality management ....................................................... 16
2.2 Principles of limit state design .................................................................................17
2.3 Basic variables ..........................................................................................................17
2.3.1 Actions and environment influences ..................................................................................... 17
2.3.2 Material and product properties ............................................................................................ 17
2.3.3 Deformations of concrete ...................................................................................................... 17
2.3.4 Geometric data ...................................................................................................................... 17
2.4 Verification by the partial factor method .................................................................17
2.4.1 General .................................................................................................................................. 17
2.4.2 Design values ........................................................................................................................ 18
2.4.3 Combinations of actions ........................................................................................................ 18
2.4.4 Verification of static equilibrium............................................................................................. 18
2.5 Design assisted by testing .......................................................................................18
2.6 Supplementary requirements for foundations ........................................................18
2.7 Requirements of fixings............................................................................................18
NA.2.8 Documentation ....................................................................................................18
NA.2.8.1 Scope .............................................................................................................................. 18
NA.2.8.2 Drawings ......................................................................................................................... 19
NA.2.8.3 Design analysis ............................................................................................................... 19
NA.2.8.4 Specification of works ..................................................................................................... 19
3 Materials......................................................................................................................... 19
3.1 Concrete ....................................................................................................................19
3.1.1 General .................................................................................................................................. 19
3.1.2 Strength ................................................................................................................................. 19
3.1.3 Deformation characteristics ................................................................................................... 19
3.1.4 Creep and shrinkage ............................................................................................................. 19
3.1.5 Stress-strain curve for non-linear methods of analysis and for strain calculations ............... 19
3.1.6 Design compressive and tensile strengths ........................................................................... 19
3.1.7 Stress-strain curve for section design ................................................................................... 19
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
3.1.8 Flexural tensile strength ........................................................................................................ 19
3.1.9 Confined concrete ................................................................................................................. 20
3.2 Reinforcing steel .......................................................................................................20
3.2.1General ................................................................................................................................... 20
3.2.2 Properties .............................................................................................................................. 20
3.2.3 Strength ................................................................................................................................. 20
3.2.5 Welding ................................................................................................................................. 20
3.2.6 Fatigue .................................................................................................................................. 20
3.2.7 Stress-strain curve for section design ................................................................................... 20
3.3 Prestressing steel .....................................................................................................20
3.3.1General ................................................................................................................................... 20
3.3.2 Properties .............................................................................................................................. 21
3.3.3 Strength ................................................................................................................................. 21
3.3.4 Ductility characteristics .......................................................................................................... 21
3.3.5 Fatigue .................................................................................................................................. 21
3.3.6 Stress-strain curve for section design ................................................................................... 21
3.3.7 Prestressing tendons in sheaths ........................................................................................... 21
3.4 Prestressing devices ................................................................................................21
3.4.1 Anchorages and couplers ..................................................................................................... 21
3.4.2 External non-bonded tendons ............................................................................................... 21
3.4.2.1 General............................................................................................................................... 21
3.4.2.2 Anchorages ........................................................................................................................ 21
RV 3.5 Materials for reinforcement using adhesive bonding .......................................21
RV 3.6 Component to be reinforced ...............................................................................22
RV 3.7 Bonded CFRP plates ...........................................................................................22
RV 3.8 CFRP plates bonded in indent cuts....................................................................22
RV 3.9 Steel tabs .............................................................................................................22
RV 3.10 Bonded CF sheeting..........................................................................................23
RV 3.10.1 Bending reinforcement .................................................................................................. 23
RV 3.10.2 Shear reinforcement...................................................................................................... 23
RV 3.10.3 Column reinforcement ................................................................................................... 23
4. Durability and cover to reinforcement ...................................................................... 23
4.1 General.......................................................................................................................23
4.2 Environmental conditions ........................................................................................23
4.3 Requirements for durability ......................................................................................23
4.4 Analysis .....................................................................................................................23
5. Structural analysis....................................................................................................... 24
5.1 General.......................................................................................................................24
5.1.1 General requirements ........................................................................................................... 24
5.1.2 Special requirements for foundations ................................................................................... 24
5.1.3 Load cases and combinations............................................................................................... 24
5.1.4 Second order effects ............................................................................................................. 24
5.2 Geometric imperfections ..........................................................................................24
5.3 Idealizations and simplifications ..............................................................................24
5.3.1 Structural models for overall analysis ................................................................................... 24
5.3.2 Geometric data ...................................................................................................................... 24
5.4 Linear-elastic analysis ..............................................................................................25
5.5 Linear elastic analysis with limited redistribution ..................................................25
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
5.6 Plastic analysis .........................................................................................................25
5.6.1 General .................................................................................................................................. 25
5.6.2 Plastic analysis for beams, frames and slabs ....................................................................... 25
5.6.3 Rotation capacity ................................................................................................................... 25
5.6.4 Design with strut and tie models ........................................................................................... 25
5.7 Non-linear analysis ...................................................................................................25
5.8 Analysis of second order effects with axial load ....................................................25
5.8.1 Definitions .............................................................................................................................. 25
5.8.2 General .................................................................................................................................. 25
5.8.3 Simplified criteria for second order effects ............................................................................ 25
5.8.4 Creep ..................................................................................................................................... 25
5.8.5 Methods of analysis .............................................................................................................. 26
5.8.6 General method..................................................................................................................... 26
5.8.7 Method based on nominal stiffness....................................................................................... 26
5.8.8 Method based on nominal curvature ..................................................................................... 26
5.8.9 Compression members with biaxial eccentricity ................................................................... 26
5.9 Lateral shift of slender beams ..................................................................................26
5.10 Prestressed members and structures ...................................................................26
5.10.1General ................................................................................................................................. 26
5.10.2 Prestressing force during tensioning ................................................................................... 26
5.10.3 Prestress force .................................................................................................................... 27
5.10.4 Immediate losses of prestress for pre-tensioning ............................................................... 27
5.10.5 Immediate losses of prestress for post-tensioning.............................................................. 27
5.10.6 Time dependent losses of prestress for pre- and post-tensioning ...................................... 27
5.10.7 Consideration of prestress in analysis ................................................................................ 27
5.10.8 Ultimate limit state ............................................................................................................... 27
5.10.9 Effects of prestressing at serviceability limit state and limit state of fatigue ....................... 27
5.11 Analysis for some particular structural members ................................................27
RV 5.12 Verification of shear tension at plate end ........................................................27
6 Ultimate limit states (ULS) ........................................................................................... 28
6.1 Bending with or without axial force .........................................................................28
RV 6.1.1 Reinforcement using bonded CFRP plates and CF sheeting for components subjected
primarily to bending stress ............................................................................................. 28
RV 6.1.2 Reinforcement with bonded steel tabs for components predominantly subject to bending
stress .............................................................................................................................. 42
RV 6.1.3 Bending reinforcement using CFRP plates bonded in indent cuts ................................. 45
RV 6.1.4 Column reinforcement using confinement ...................................................................... 48
6.2 Shear force ................................................................................................................52
6.2.1 Analysis ................................................................................................................................. 52
6.2.2 Members not requiring design shear reinforcement ............................................................. 52
6.2.3 Members requiring design shear reinforcement ................................................................... 52
6.2.4 Shear between web and flange............................................................................................. 53
6.2.5 Shear transfer in joints .......................................................................................................... 53
RV 6.2.6 Shear reinforcement ........................................................................................................ 54
RV 6.2.7 End links to prevent breakage due to shift ...................................................................... 56
6.3 Torsion .......................................................................................................................57
6.4 Punching shear .........................................................................................................57
6.4.1 General .................................................................................................................................. 57
6.4.2 Loaded areas and critical sections used in analyses ............................................................ 57
6.4.3 Analysis ................................................................................................................................. 57
6.4.4 Punching shear resistance of slabs and column bases without shear reinforcement .......... 57
6.4.5 Punching shear resistance of slabs and column bases with shear reinforcement ............... 57
6.5 Design with strut and tie models .............................................................................57
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
6.5.1 General .................................................................................................................................. 57
6.5.2 Struts ..................................................................................................................................... 57
6.5.3 Ties ........................................................................................................................................ 57
6.5.4 Design of nodes .................................................................................................................... 57
6.6 Anchorages and laps ................................................................................................58
6.7 Partial area loading ...................................................................................................58
6.8 Fatigue analysis ........................................................................................................58
6.8.1 General .................................................................................................................................. 58
6.8.2 Internal forces and stresses for fatigue verification............................................................... 58
6.8.3 Combination of actions .......................................................................................................... 58
6.8.4 Verification procedure for reinforcing and prestressing steel ................................................ 58
6.8.5 Verification using damage equivalent stress range .............................................................. 58
6.8.6 Other verifications ................................................................................................................. 58
6.8.7 Verification of concrete under compression or shear............................................................ 58
RV 6.8.8 CFRP plates bonded to a surface ................................................................................... 58
RV 6.8.9 Bonded steel tabs ........................................................................................................... 61
RV 6.8.10 CFRP plates bonded in indent cuts .............................................................................. 61
7 Serviceability limit states (SLS) .................................................................................. 62
7.1 General.......................................................................................................................62
7.2 Limitation of stresses ...............................................................................................62
7.3 Crack control .............................................................................................................63
7.3.1 General .................................................................................................................................. 63
7.3.2 Minimum reinforcement for limitation of crack width ............................................................. 63
7.3.3 Control of cracking without detailed analysis ........................................................................ 63
7.3.4 Calculation of crack width ..................................................................................................... 63
RV 7.3.5 Crack width-limiting effect of bonded plates ................................................................... 63
7.4 Limitation of deformations .......................................................................................65
7.4.1 General .................................................................................................................................. 65
7.4.2 Cases where calculations may be omitted ............................................................................ 66
7.4.3 Checking deflections by calculation ...................................................................................... 66
8 Detailing of reinforcement and prestressing tendons — general ......................... 66
8.1 General.......................................................................................................................66
8.2 Spacing of reinforcing steel bars .............................................................................66
RV 8.2.1 Spacing of plates ............................................................................................................. 66
8.3 Bending of steel ........................................................................................................68
RV 8.3.1 Bending of the bonded reinforcement ............................................................................. 68
8.4 Anchorage of longitudinal reinforcement................................................................68
8.4.1 General .................................................................................................................................. 68
8.4.2 Ultimate bond stress ............................................................................................................. 68
8.4.3 Basic anchorage length ......................................................................................................... 68
8.4.4 Design anchorage length ...................................................................................................... 68
RV 8.4.5 Anchorage of the bonded reinforcement ......................................................................... 68
RV 8.4.6 Base dimension of the adhesive bond for reinforcement bonded to a surface ............... 68
RV 8.4.7 Base dimension of the adhesive bond in indent cuts ...................................................... 69
8.5 Anchorage of links and shear reinforcement ..........................................................69
8.6 Anchorage by welded bars .......................................................................................69
8.7 Laps and mechanical couplers ................................................................................69
8.7.1 General .................................................................................................................................. 69
8.7.2 Laps ....................................................................................................................................... 69
8.7.3 Lap length.............................................................................................................................. 69
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
8.7.4 Transverse reinforcement in the lap zone ............................................................................. 70
8.7.5 Laps for welded mesh fabrics made with ribbed wires ......................................................... 70
RV 8.7.6 Plate lap joints ................................................................................................................. 70
8.8 Additional rules for large diameter bars ..................................................................71
8.9 Bundled bars .............................................................................................................71
8.9.1 General .................................................................................................................................. 71
8.9.2 Anchorage of bundles of bars ............................................................................................... 71
8.9.3 Lapping bundles of bars ........................................................................................................ 71
8.10 Prestressing tendons ..............................................................................................71
8.10.1 Arrangement of prestressing tendons and ducts ................................................................ 71
8.10.2 Anchorage of pre-tensioned tendons .................................................................................. 71
8.10.3 Anchorage zones of post-tensioned or unbonded members .............................................. 71
8.10.4 Anchorages and couplers for prestressing tendons............................................................ 71
8.10.5 Deviators ............................................................................................................................. 71
9 Detailing arrangements for structural members ...................................................... 71
9.1 General.......................................................................................................................71
9.2 Beams ........................................................................................................................72
9.2.1 Longitudinal reinforcement .................................................................................................... 72
9.2.2 Shear reinforcement .............................................................................................................. 72
9.2.3 Torsion reinforcement ........................................................................................................... 72
9.2.4 Surface reinforcement ........................................................................................................... 72
9.2.5 Indirect supports .................................................................................................................... 72
RV 9.2.6 Links of the bonded reinforcement .................................................................................. 72
RV 9.2.7 Execution of bonded links ............................................................................................... 73
9.3 Solid slabs .................................................................................................................75
9.3.1 Flexural reinforcement .......................................................................................................... 75
9.3.2 Shear reinforcement .............................................................................................................. 75
9.4 Flat slabs ...................................................................................................................75
9.4.1 Slab at internal columns ........................................................................................................ 75
9.4.2 Slab at edge columns ............................................................................................................ 75
9.4.3 Punching shear reinforcement .............................................................................................. 75
9.5 Columns .....................................................................................................................76
9.5.1 General .................................................................................................................................. 76
9.5.2 Longitudinal reinforcement .................................................................................................... 76
9.5.3 Shear reinforcement .............................................................................................................. 76
RV 9.5.4 Column reinforcement ..................................................................................................... 76
9.6 Walls...........................................................................................................................76
9.6.1 General .................................................................................................................................. 76
9.6.2 Vertical reinforcement ........................................................................................................... 76
9.6.3 Horizontal reinforcement ....................................................................................................... 76
9.6.4 Shear reinforcement .............................................................................................................. 77
9.7 Deep beams ...............................................................................................................77
9.8 Foundations...............................................................................................................77
9.8.1 Pile caps ................................................................................................................................ 77
9.8.2 Column and wall footings ...................................................................................................... 77
9.8.3 Tie beams.............................................................................................................................. 77
9.8.4 Column footing on rock ......................................................................................................... 77
9.8.5 Bored piles ............................................................................................................................ 77
9.9 Regions with discontinuity in geometry or action (D regions) ..............................77
9.10 Limitation of damage due to accidental actions ...................................................77
9.10.1 General ................................................................................................................................ 77
9.10.2 Proportioning of ties ............................................................................................................ 77
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
9.10.3 Continuity and anchorage of ties ........................................................................................ 78
10 Additional rules for precast concrete elements and structures .......................... 78
11 Lightweight aggregate concrete structures ........................................................... 78
12 Plain and lightly reinforced concrete structures ................................................... 78
Annex RV K: Recommended system coefficients (informative) .............................. 79
RV K1 Values for reinforcements created by adhesive bonding: ................................79
RV K2 System coefficient for columns: .........................................................................79
Annex RV L Determination of cross-section values (informative) ........................... 80
RV L1 Ultimate limit state ...............................................................................................80
RV L1.1 General............................................................................................................................. 80
RV L1.2 Rectangular cross-sections .............................................................................................. 80
RV L1.3 T-beams ........................................................................................................................... 80
RV L2 In the ultimate limit state .....................................................................................81
RV L3 Approximation method for the ultimate limit state ............................................81
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
1General
1.1Scope
1.1.1 Scope of Eurocode 2
No additions or amendments
1.1.2 Scope of Part 1-1 of Eurocode 2
No additions or amendments
RV 1.1.3 Scope of DAfStb Guideline Reinforcement of concrete parts with adhesive bonding
(RV1) This part of the Guideline contains basic rules for the design, calculation and design of
reinforcement measures with adhesive bonding for plain, reinforced and prestressed concrete
structures.
(RV 2) This part of the Guideline does not apply to:

The reinforcement of lightweight aggregate concrete structures;

The reinforcement of lightweight aggregate concrete structures using prestressed fibre
composite materials.
(RV3) The requirements for products and systems for reinforcement of concrete components in
accordance with general building inspectorate approvals shall apply (see also Part 2 of this Guideline).
(RV4) Bonded reinforcement may be used for components subject to predominantly static and nonstatic actions, in accordance with DIN EN 1990, Sections 1.5.3.11, 1.5.3.12 and Section 4.1.
(RV5) Application of this part of the Guideline requires component strength of at least C12/15
determined in accordance with DIN EN 13791.
1.2 Normative references
1.2.1 General reference standards
No additions or amendments
1.2.2 Other reference standards
In addition to the documents cited in DIN EN 1992-1-1 with DIN EN 1992-1-1/NA, the following
documents are necessary for use of this document.
DIN EN 1504-2, Products and systems for the protection and repair of concrete structures Definitions, requirements, quality control and evaluation of conformity - Part 2: Surface protection
systems for concrete
DIN EN 1993-1-1, Eurocode 3: Design of steel structures - Part 1-1: General rules and rules for
buildings
DIN EN 1993-1-9, Eurocode 3: Design of steel structures - Part 1-9: Fatigue
DIN EN 1993-1-8, Eurocode 3: Design of steel structures - Part 1-8: Design of joints
DIN 18195, Waterproofing of buildings
DIN V 18026, Surface protection systems for concrete products according to DIN EN 1504-2:2005-01
DAfStb Guideline “Protection and repair of concrete components”
DBV-Merkblatt “Bauen im Bestand/Beton und Betonstahl” [DBV Code on building with existing
parts/concrete and reinforcing steel]
1.3 Assumptions
(RV2) The assumptions according to DIN EN 1990 and DIN EN 1992-1-1 shall also apply in this
Guideline. This Guideline contains additional and deviating rules with regard to DIN EN 1992-1-1 on
reinforcement of concrete parts with adhesive bonding.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
1.4 Distinctions between principles and application rules
No additions or amendments
1.5Definitions
1.5.1General
No additions or amendments
1.5.2 Additional terms and definitions used in this Standard
RV 1.5.2.27 Adhesive
Non-metallic material that can join materials through surface adhesion for the joint to possess
sufficient internal strength (cohesion).
RV 1.5.2.28 Sheeting
Special textile surface structure used for reinforcement in fibre composite materials. Sheeting consists
of parallel fibre bundles.
RV 1.5.2.29 Bonded reinforcement
Materials with tensile strength bonded to the concrete using an adhesive to make the bond shearresistant.
RV 1.5.2.30 Plates bonded into indent cuts
Here the plates are bonded by adhesive into indents that were cut into the concrete.
RV 1.5.2.31 Plate
Unidirectional fibre composite materials premade at the factory and thermally hardened.
RV 1.5.2.32 Bonded links
Steel tabs or fibre composite material bonded to the component surface to enhance shear strength,
enveloping the component in curtailed or non-curtailed form.
RV 1.5.2.33 Breakage due to shift
Special type of breakage occurring at the plate end of bonded reinforcements, where a shift in tensile
force may pull off the concrete cover and the entire bonded reinforcement.
RV 1.5.2. 34 Large-area defective spot
For individual areas of L ≥ 500 mm in the direction of the longitudinal axis of the reinforcement or, for
levelling layers on a steel tab, bonded CFRP plate, sheeting or CFRP plates bonded in indent cuts
with a total length L ≥ 20 % of individual plate length.
RV 1.5.2.35 Small-area defective spot
A defective spot that is not a large-area defective spot.
RV 1.5.2.36 CFRP / CF
Carbon fibre reinforced plastic (CFRP) is a fibre-plastic composite material in which carbon fibres are
embedded in a plastic matrix for reinforcement.
Carbon fibres (CF) are fibres that are industrially manufactured from carbon materials.
RV 1.5.2.37 Non-curtailed link
Bonded link where only the tension zone is closed. In this link, tensile forces are lead through the
composite into the compression zone.
1.6 Symbols
In addition to the documents cited in DIN EN 1992-1-1 with DIN EN 1992-1-1/NA, the following
symbols are necessary for use of this document
Latin upper case symbols
Ac,eff
(sectional) area of zone of concrete section in which reinforcement is effective
Ai
ideal sectional area
10
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Fbsm
FCEd
FDLk,BL
FLEd
FLRd
FLuk
Fs
Fsd
Fsyd
sectional area of bonded reinforcement
sectional area of shear reinforcement
cross-sectional diameter of the compression member
diameter of the core cross-section confined by reinforcing steel
total link rigidity
confinement rigidity of the fibre composite material
characteristic modulus of elasticity of the bonded reinforcement
mean modulus of elasticity of the bonded reinforcement
modulus of elasticity of the shear reinforcement
design composite material strength of the bonded reinforcement
design maximum composite material strength of the bonded reinforcement at the anchoring
point
mean bond strength of the reinforcement
concrete compressive force
plate force at Point D at the crack edge subject to the lesser load
design concentrated force of the bonded reinforcement
maximum tensile force of the bonded reinforcement
characteristic plate breakage force
tensile force of reinforcing steel
design tensile force of reinforcing steel
design tensile force of reinforcing steel at yield point
Fu(b)
self-induced contact pressure
Fu,2
self-induced contact pressure for b = 0.4
Fu,4
Füd,max
self-induced contact pressure for b = 0.8
tension force that can be transmitted at the lap joint of the bonded reinforcement
AL
ALw
D
Dc
EIS,g
Ejl
ELk
ELm
ELW
FbLRd
FbLRd,max
FDLk,BL resistance of plate force difference in Point D
FGLk,BL resistance of plate force difference in Point G
FL,1
increase in bond strength due to curtailment of link
FLE,equ plate force difference under quasi-constant load
FLEd
design place force change
FLEdO
plate force difference under top load
FLEdU
plate force difference under bottom load
FLk,BF
bond strength resistance at the intermediate crack element due to friction
FLk,BL base bond strength at the intermediate crack element
FLk,KF
bond strength resistance at the intermediate crack element due to curvature
FLR,fat1 resistance to plate force difference that will not cause fatigue failure
FLR,fat2 resistance stress amplitude of the plate force at the crack edge subject to the higher load
FLRd
Ii
design resistance to change in plate force
theoretical sectional moment of inertia of the reinforced concrete support
K
Mcr
MEqp
factor to increase curvature due to creep
cracking moment of the reinforced concrete cross-section
first order bending moment due to quasi-permanent combination of actions taking into
account imperfections
design resistance moment
axial force due to quasi-permanent combination of actions
temperature defining the glass transition zone
contact component of concrete parts with shear reinforcement
MRd
NEqp
Tf
Vccd
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Vct
Vc,LE
VEd
VL
VRd
VRd,c
VRd,c,LE
VRd,L
VRd,s
VRd.cc
Vs
Wc,0
shear resistance for components without shear reinforcement
shear force at which breakage due to shift without curtailment of link does not yet occur
design concentrated shear force
shear resistance of the shear reinforcement
design resistance to effective shear
design shear resistance of components without shear reinforcement
design resistance against breakage due to shift
design shear reinforcement component
design shear reinforcement component in parts with shear reinforcement
design loadbearing capacity component of the concrete in parts with shear reinforcement
shear resistance of internal shear reinforcement
resistance moment of the concrete cross-section in the uncracked state
Latin lower case symbols
a1
aL
aL
ar
as
bc
beff,i
bL
bL,eff
bLw
bs
c
da
daL
dL
e0
ei
etot
fb
fbd
fbk
fbLd
fbLk
fbLk,max
fbLwd
fbsm
fcck
fck(tV0)
fck*
fcm(tV0)
magnitude of shift of tension envelope
distance between axes of bonded reinforcement
distance of the bonded reinforcement from the support axis
distance of the bonded reinforcement from the free component edge for CFRP plates
bonded in indent cuts
axis distance of reinforcement embedded in concrete
width of concrete component to be reinforced
effective flange width
width of the bonded reinforcement
effective plate width when using several plates for analysis of increase in bond strength due
to curtailment of link
width of the shear reinforcement
width of cut for CFRP plates bonded in indent cuts
concrete cover
effective static depth of the reinforcing steel reinforcement at the support
effective static depth of the bonded reinforcement at the support
effective static depth of the reinforcement
planned first order biaxial eccentricity
additional accidental biaxial eccentricity according to DIN EN 1992-1-1
first order biaxial eccentricity
bond strength
design bond strength
characteristic bond strength
design bond strength of the reinforcement
characteristic bond strength of the reinforcement‚
characteristic maximum bond strength of the reinforcement at the end anchorage
design strength of shear reinforcement due to bond effect
mean bond stress of the reinforcing steel reinforcement
characteristic compressive strength of confined concrete
characteristic unconfined concrete compressive strength at the time of reinforcement (to be
determined by measurements on the component)
characteristic value of a simple stress-strain curve for design
mean unconfined concrete compressive strength at the time of load application (to be
determined by measurements on the component)
12
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
fct,eff
fctk
fctm
fctm,surf
fctm,surf,is
fcti,surf,is
fcufrpk
fGck
fGtk
fGud,Lw
fGuk,Lw
fGuk,Lw,max
fLud
fLuk
fLw
fLwd
fLwd,G
fLwd,GF
fLwd,GS
fLyd
fywk
hc,ef
hLw
kL
kL,eff
ks
ks,eff
kt
lbL
lbL,lim
lbL,max
lbs
le,0
ls,A
ls,U
lu,Lw
lu,Lw,max
lü,max
nsi
p
rc
s
saLr
scr,max
mean effective axial tensile strength of concrete
characteristic axial tensile strength of concrete
mean axial tensile strength of concrete
calculated mean axial tensile surface strength of concrete
mean axial tensile surface strength of concrete determined in-situ in accordance with DIN
EN 1542
individual axial tensile surface strength of concrete determined in-situ in accordance with
DIN EN 1542
characteristic resistance to concrete compressive stress resulting from the confinement
effect of fibre composite material in the event of its failure
compressive strength of the adhesive
tensile strength of the adhesive
design strength of the lap joint
characteristic strength of the lap joint
maximum characteristic strength of the lap joint
design tensile strength of the plate
characteristic material strength of the bonded reinforcement
strength of the shear reinforcement
design strength of the shear reinforcement
design strength of the shear reinforcement due to material strength of overlaps or curves
design strength of the shear reinforcement due to material strength in fibre composite
reinforcements
design strength of the shear reinforcement due to material strength in steel tabs
design yield strength of steel tabs
characteristic yield strength of the reinforcing steel confinement by links or hooping
height of zone of concrete section in which reinforcement is effective
height of the shear reinforcement
bond factor for CFRP plates bonded in indent cuts
bond factor for CFRP plates bonded in indent cuts taking into account time effects
bond factor for reinforcement embedded in concrete
bond factor for embedded reinforcements taking into account time effects
bond creep factor
bond length of the bonded reinforcement
bond length related to anchorage analysis
effective bond length
bond length of the reinforcing steel
dispersion length of the reinforcing steel
leg length of the curtailment angle
leg length of the curtailment link
lap length of the link
effective lap length of the link
effective lap length of the bonded reinforcement
number of reinforcing steels
reduction in shear compression due to deviating zones of influence of the confining
reinforcements
curve radius
spacing of links along the longitudinal axis of the component or helix height
slip of bonded reinforcement at the bending crack closest to the point of zero moment
maximum crack spacing under working load
13
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
sL0k
sLr
sLw
sr
tG
tL
tLW
ts
tw,eff
maximum slip according to bilinear bond approach
slip of the bonded reinforcement
axis distance of shear reinforcement
spacing of bending cracks
adhesive thickness
theoretical thickness of the bonded reinforcement
theoretical thickness of the shear reinforcement
depth of cut for CFRP plates bonded in indent cuts
thickness of loaded reinforcing steel confinement
t
xa
zaL
zas
zjs
residual life span in days
compression zone height at the support
inner lever arm of the plate at the support
inner lever arm of the reinforcing steel at the support
distance (+/-) of reinforcing steel longitudinal bar j from centre of gravity of the gross
concrete cross-section
inner lever arm of the bonded reinforcement
mean inner lever arm
inner lever arm of the reinforcing steel
zL
zm
zs
Greek lower case symbols

1
3
b
E
F
k
L
N
r
s
s
reduction factor for resistance stress amplitude
T
reduction factor to take into account the influence of temperature fluctuations on the
loadbearing capacity of the confinement
Z
reduction factor taking into account the creep behaviour
Zeit
continuous creep reduction factor for CF sheeting (shear reinforcement)

factor taking into account the properties of the compression member
(fcm)
factor taking into account the effects of concrete compressive strength on the creep base
number
0,k
c(t)
factor taking into account the load level
H
aLRk
aLRk,lim
asRk
factor describing the influence of moisture
completeness coefficient of the tension block
factor describing the influence of higher concrete strengths on moisture
ratio between bonded reinforcement width and web width
reduction factor for fatigue analysis
reduction factor taking into account the influence of moisture
increase factor taking into account creep distribution spread
bond factor for CFRP plates bonded in indent cuts
bond factor for anchorage analysis
reduction factor taking into account the deviation of CF sheeting
bond factor for reinforcement embedded in concrete
ratio of the moduli of elasticity of the reinforcing steel longitudinal reinforcement and the nonconfined concrete
factor describing the creep development over time when loads are applied to the reinforced
component
strain of the reinforcement for anchorage analysis
strain of the reinforcement for anchorage analysis as a function of maximum bond strength 
strain of the reinforcing steel for anchorage analysis 
14
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
cc(t)
cm
cr1
cu
juak
creep deformation in longitudinal direction of the support during time t
juk
LII
Luk
Lm
Lr1
LRd,max
Lud
LW
L
s
y
yk
characteristic ultimate strain of the confined reinforcement at the component
w
BA
BE
BG
LG
LL
L
ef
 Lb
b1k
b2
b3
b4
bsk
fl
bar diameter of helical reinforcement
h
factor for calculating the resistance to plate force change from component curvature at the
intermediate crack element (simplified analysis)
K
factor for calculating the resistance to plate force change from component curvature at the
intermediate crack element (detailed analysis)
l
factor taking into account several bonded CFRP plates/steel tabs for increase in bond
strength due to curtailment of link
L1
factor for calculating the resistance to plate force change from adhesive bond at the
intermediate crack element (simplified analysis)
LF
factor for calculating the resistance to plate force change from bond friction at the
intermediate crack element (simplified analysis)
R
sys
t
reduction factor due to curve radius
mean strains of the concrete
concrete strain at the crack edge subject to the lesser load
ultimate strain of the confined concrete
ultimate strain of the confined reinforcement at the component taking onto account timedependent deformation
strain of the plate in the crack using Bernoulli’s theory on beams assumptions
characteristic ultimate strain of the bonded reinforcement
mean strain of the bonded reinforcement
strain of the bonded reinforcement at the crack edge subject to the lesser load
strain of the bonded reinforcement
design maximum strain of the bonded reinforcement
strain of the shear reinforcement
strain of the bonded reinforcement
strain of the reinforcing steel
yield strain in the reinforcing steel
strain in the reinforcing steel longitudinal reinforcement on reaching the characteristic yield
strain
bond safety factor, bonded on
bond safety factor, bonded in indent cuts
safety factor for adhesive bonds of steel on steel or CFRP on CFRP
safety factor for CF sheeting
safety factor for CFRP plates
factor taking into account the different elastic stiffnesses and bond strengths
effective creep
adjustment factor for effective bond length
bond coefficient for bonded reinforcement
bond coefficient for bonded reinforcement
bond coefficient for bonded reinforcement
bond coefficient for bonded reinforcement
bond coefficient for reinforcement embedded in concrete
conversion factor between flexural tensile strength and centric tensile strength of the
concrete
product-specific system coefficient
factor for determining the steel tab thickness
15
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
vb
factor for calculating the mean bond stress of the reinforcing steel as a function of the bond
conditions
vb1
factor for calculating the mean bond stress of the reinforcing steel as a function of the bond
conditions
vb2
factor for calculating the mean bond stress of the reinforcing steel as a function of the bond
conditions



c
factor (plates bonded in indent cuts)
t
reference angle describing the stress distribution in the loaded reinforcing steel longitudinal
reinforcement subject to tension
L
Lw
s1
wy
Eqp
sr
b
bck
bGk
bLd
L1k
LFk
Lm
sm
1
2
reinforcement level of bonded reinforcement 
L
ratio of bond strength of the bonded reinforcement to embedded reinforcement
referenced compressive stress of concrete
reference angle describing the tension block in the cross-section 
reference angle describing the stress distribution in the loaded reinforcing steel longitudinal
reinforcement subject to compression
reinforcement level of shear reinforcement
level of tensile reinforcement of reinforced concrete
shear reinforcement level
longitudinal compressive stress of concrete under quasi-permanent combination of actions
stress in the reinforcing steel on cracking 
bond stress
bond stress of concrete with plates bonded in indent cuts
bond stress of adhesive of plates bonded in indent cuts
design bond stress
maximum bond stress of bilinear approach
frictional bond stress
mean bond stress of the bonded reinforcement
mean bond stresses of reinforcing steel
factor taking into account the reduction in curvature with an increase in compressive force Nu
factor taking into account the geometry of the compression member and strain of the
confining reinforcement
2 Basis of design
2.1 Requirements
2.1.1 Basic requirements
(RV 4) Approval of the product combination of adhesive and reinforcement (system) used shall be
furnished in the form of a general building inspectorate approval.
(RV 5) Proof of fire resistance of a component reinforced according to this Guideline that is required
for the application shall be furnished in accordance with DIN EN 1992-1-2 and the National Annex
without including the reinforcement effect of the adhesive bond. If it is protected from thermal and fire
exposure by a fire barrier approved by a building inspectorate, this proof shall be furnished according
to the rules of general building inspectorate approval.
2.1.2 Reliability management
No additions or amendments
2.1.3 Design working life, durability and quality management
No additions or amendments
16
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
2.2 Principles of limit state design
No additions or amendments
2.3 Basic variables
2.3.1 Actions and environment influences
2.3.1.1 General
No additions or amendments
2.3.1.2 Thermal effects
(RV 4) After approval, no forces may be allocated to the bonded reinforcement above temperature Tf.
Note: Fire protection systems approved by a general building inspectorate for bonded reinforcements
shall be used for the fire protection of the bonded reinforcement.
2.3.1.3 Differential settlements/movements
No additions or amendments
2.3.1.4 Prestress
No additions or amendments
2.3.2 Material and product properties
2.3.2.1 General
(RV 3) Requirements of the component to be reinforced are listed in Section RV 3.6.
(RV 4) The requirements for the products and systems for reinforcement are included in Part 2 and in
Sections RV 3.7 through RV 3.10.
2.3.2.2 Creep and shrinkage
(RV 4) To prevent excessive creep, the continuous bond strength and maximum usage temperature,
which are dependent on the construction kit, are specified in the general building inspectorate
approvals.
(RV 5) Time-dependent deformations of column reinforcement shall be considered in accordance with
Section 6.1.4.
2.3.3 Deformations of concrete
No additions or amendments
2.3.4 Geometric data
2.3.4.1 General
No additions or amendments
2.3.4.2 Supplementary requirements for cast in place piles
No additions or amendments
2.4 Verification by the partial factor method
2.4.1 General
No additions or amendments
17
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
2.4.2 Design values
2.4.2.1 Partial factor for shrinkage action
No additions or amendments
2.4.2.2 Partial factor for prestress
No additions or amendments
2.4.2.3 Partial factor for fatigue loads
No additions or amendments
2.4.2.4 Partial factor for materials
(RV 4) In addition to DIN EN 1992-1-1, the partial safety factors in Section 2.1 shall be used for
bonded reinforcement. The safety factor in accordance with DIN EN 1993-1-1 and its National Annex
shall be used for steel tabs.
Table RV 2.1: Partial safety factors for bonded reinforcement in the ultimate limit state
Colum
n
Line
1
2
3
1
2
3
4
5
6
Design situation
For
CFRP
plates
For CF
sheetin
g
Bond reinforcem
ent
bonded on
Bond reinforceme
nt bonded in
indent cuts
Bond - bonding of
steel on steel or
CFRP on CFRP
LL
LG
BA
BE
BG
1.2
1.35
1.5
1.3
1.3
1.05
1.1
1.2
1.05
1.05
Designation
Permanent and
temporary
Extraordinary
2.4.2.5 Partial factors for materials for foundations
No additions or amendments
2.4.3 Combinations of actions
No additions or amendments
2.4.4 Verification of static equilibrium
No additions or amendments
2.5 Design assisted by testing
No additions or amendments
2.6 Supplementary requirements for foundations
No additions or amendments
2.7 Requirements of fixings
No additions or amendments
NA.2.8 Documentation
NA.2.8.1 Scope
No additions or amendments
18
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
NA.2.8.2 Drawings
(RV 4)P The components, the reinforcement to be bonded and all fastening elements shall be
represented clearly on the drawings. All representations shall match the data in the static calculation
and contain all dimensions necessary for the execution of the components and testing of the
calculations.
(RV 5)P The execution plans shall contain in particular:

the required adhesive pull strengths;

designations and components of the reinforcement system;

number, dimensions and location of the bonded reinforcement; mutual distance; arrangement,
type and position of the mechanical joining devices;

for CFRP plates bonded in indent cuts: depth and width of the cuts including tolerances;

special measures for quality assurance, as applicable.
NA.2.8.3 Design analysis
No additions or amendments
NA.2.8.4 Specification of works
No additions or amendments
3 Materials
3.1 Concrete
3.1.1 General
(RV 3)P This Guideline shall only apply to components made of normal weight concrete.
3.1.2 Strength
(RV 10)P The surface tensile strength of concrete fctm,surf shall be determined in accordance with Part 4
of this Guideline.
(RV 11) As the components to be reinforced are existing components, converting the concrete
strength for predimensioning might be necessary in some cases, which can be done in accordance
with DBV-Merkblatt “Bauen im Bestand/Beton und Betonstahl” [DBV Code on building with existing
parts/concrete and reinforcing steel].
3.1.3 Deformation characteristics
No additions or amendments
3.1.4 Creep and shrinkage
No additions or amendments
3.1.5 Stress-strain curve for non-linear methods of analysis and for strain calculations
No additions or amendments
3.1.6 Design compressive and tensile strengths
No additions or amendments
3.1.7 Stress-strain curve for section design
No additions or amendments
3.1.8 Flexural tensile strength
No additions or amendments
19
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
3.1.9 Confined concrete
No additions or amendments
3.2 Reinforcing steel
3.2.1General
(RV 6) This Guideline may be applied to components with reinforcing steels and reinforcement
elements that do not meet the requirements of DIN EN 10080 or DIN 488.
3.2.2 Properties
(RV 7) For reinforcement of existing components according to this Guideline, the existing reinforcing
steels need not comply with DIN EN 1992-1-1 Section 3.2.2 (2); (3); (4); (5) and (6).
(RV 8) The properties of existing reinforcing steels according to DIN EN 1992-1-1 Section 3.2.2 (1)
should be known.
(RV 9) For reinforcing steels from 1952 on, the yield points may be used as characteristic values.
Approximate values for older reinforcing steels and reinforcement elements may be taken from DBVMerkblatt “Bauen im Bestand/Beton und Betonstahl” [DBV Code on building with existing
parts/concrete and reinforcing steel].
(RV 10) If reinforcing steel without ribbing is used, the bonding properties of smooth steel may be
assumed.
3.2.3 Strength
No additions or amendments
3.2.5 Welding
No additions or amendments
3.2.6 Fatigue
(RV 2) Wöhler curves according to DIN EN 1992-1-1 in combination with DIN EN 1992-1-1/NA may be
used for ribbed reinforcing steels, unless different Wöhler curves have been specified in a general
building inspectorate approval. For reinforced concrete components that are reinforced only with
smooth reinforcing steel, Wöhler curves according to DIN EN 1992-1-1 in combination with
DIN EN 1992-1-1/NA may also be used. Smooth reinforcing steel reinforcement may not be used for
verification of fatigue in light-weight concrete parts.
3.2.7 Stress-strain curve for section design
No additions or amendments
3.3 Prestressing steel
3.3.1General
(RV 12) For older prestressing steels, the danger potential from stress corrosion cracking shall be
assessed. The following prestressing steels are more susceptible to stress corrosion cracking:



Heat-treated prestressing steel St 145/160, round or oval cross-section, manufacturer Felten &
Guilleaume Carlswerke AG, trade name Neptun, production period to 1965 high danger potential;
heat-treated prestressing steel St 145/160, round or oval cross-section, manufacturer Hütten- und
Bergwerke Rheinhausen AG, trade name Sigma, production period to 1965 high danger potential
(round or oval), production period to 1978 danger potential (oval only);
heat-treated Hennigsdorf prestressing steel St 140/160, round or oval cross-section,
manufacturer VEB Stahl- und Walzwerk Hennigsdorf (formerly GDR); Heat treatment process
with oil end treatment or high temperature thermo-mechanical treatment (HTMT steels),
production period to 1993 high danger potential.
20
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
3.3.2 Properties
No additions or amendments
3.3.3 Strength
No additions or amendments
3.3.4 Ductility characteristics
No additions or amendments
3.3.5 Fatigue
(RV 2) Wöhler curves according to DIN EN 1992-1-1 in combination with DIN EN 1992-1-1/NA may be
used for prestressing steels embedded in concrete, if the stress amplitude endured 2106 times and
determined in free vibration reaches a minimum tensile strength of 185 N/mm² at a top stress of 65 %.
Information on fatigue strength of prestressing steels not embedded in concrete and in free vibration
can be found in general building inspectorate approvals for prestressing steel.
3.3.6 Stress-strain curve for section design
No additions or amendments
3.3.7 Prestressing tendons in sheaths
No additions or amendments
3.4 Prestressing devices
3.4.1 Anchorages and couplers
3.4.1.1 General
No additions or amendments
3.4.1.2 Mechanical properties
No additions or amendments
3.4.1.2.1 Anchored tendons
No additions or amendments
3.4.1.2.2 Anchored devices and anchorage zones
No additions or amendments
3.4.2 External non-bonded tendons
No additions or amendments
3.4.2.1 General
No additions or amendments
3.4.2.2 Anchorages
No additions or amendments
RV 3.5 Materials for reinforcement using adhesive bonding
(RV 1) The rules in Part 2 of this Guideline shall apply.
(RV 2) The design equations are based on tests and theoretical considerations. Geometric and
material application limits were defined in this context. The following equations thus only apply for the
range given in Sections 3.6 to 3.9.
21
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV 3) If, in a design case, limit values according to Section 3.6 are exceeded or fallen short of, limit
values according to Sections 3.6 may be used for the equations if that results in a less favourable
value.
(RV 4) For construction kits consisting of adhesive and plate, the rules of general building inspectorate
approvals shall apply. Sections 3.7 to 3.9 list the material properties on which the design approaches
of this Guideline were based. General building inspectorate approvals may contain deviating rules.
RV 3.6 Component to be reinforced
(RV 1) For the components to be reinforced, compression strengths of C12/15 to C50/60 based on
DIN EN 206-1, Table 7, was assumed.
(RV 2) For a bond in accordance with Annex RV K, a maximum concrete compression strength of 58
N/mm² and a maximum mean surface tensile strength of concrete of 4 N/mm² may be used in the
design equations.
(RV 3) The design equations do not apply to component thicknesses of less than 100 mm. For
component thickness less than 100 mm, to be on the safe side, 100 mm may be used for design in
equations 6.11 and 6.17.
(RV 4) The design equations apply to components that are planned to be straight or level. The design
equations may be applied accordingly to convex component surfaces. The bonding surfaces of CFRP
plates must not have concave curvature.
RV 3.7 Bonded CFRP plates
(RV 1) The CFRP plates shall be in accordance with Part 2.
(RV 2) If the design equations of this Guideline are applied, the CFRP plates may be bonded in no
more than two layers, with the maximum thickness of the CFRP plate cross-section without the
adhesive not to exceed 3 mm.
(RV 3) The design equations assume an adhesive layer thickness between 1 mm and 5 mm.
RV 3.8 CFRP plates bonded in indent cuts
(RV 1) The CFRP plates shall be in accordance with the requirements in Part 2.
(RV 2) If the design equations of this Guideline are applied, the CFRP plates must not be bonded
twice in one indent cut. This does not apply for double plates approved by a building inspectorate.
(RV 3) The design equations assume an insert width of bs according to Equation 3.1.
tL  1 mm  bs  tL  3 mm
(RV 3.1)
(RV 4) If this Guideline is applied, the plate width shall be between 10 mm and 30 mm.
RV 3.9 Steel tabs
(RV 1) The design equations apply to steel tabs made of steels according to DIN EN 10025-2, which
are 5 mm to 15 mm in thickness.
(RV 2) The strength values for steel tabs to be used in the design equations shall be equivalent to S
235, even if a higher-strength steel is used.
(RV 3) Additionally, the following requirements regarding tab thickness tL as a function of the strength
class of the concrete foundation shall be met:
Concrete strength classes C12/15 and C16/20:
5 mm  tL  10 mm
Concrete strength class C20/25 und C50/60:
5 mm  tL  15 mm
The width of the steel tabs bL shall fulfil condition 10 x tL  bL  200 mm.
22
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
RV 3.10 Bonded CF sheeting
RV 3.10.1 Bending reinforcement
(RV 1) In principle, the design equations for bending reinforcement of bonded CFRP plates can be
applied to CF sheeting if the reinforcement meets the following conditions. To apply the design
equations, the bond factors in accordance with Section 8.4.6 shall be determined or specified by
means of approvals for the system used.
(RV 2) The elastic stiffness ELmAL per metre is limited to 20 kN/mm to 400 kN/mm.
(RV 3) CF sheeting may be bonded in a maximum of five layers.
(RV 4) The total fibre cross-section per 1 000 mm sheeting width in the total of all layers shall be
between 100 mm²/m and 1 800 mm²/m.
RV 3.10.2 Shear reinforcement
(RV 1) The bond factors according to Section 8.4.6 shall be determined or specified by means of
approvals for the system used.
(RV 2) CF sheeting may be bonded in a maximum of five layers.
RV 3.10.3 Column reinforcement
(RV 1) CF sheeting may be bonded in a maximum of ten layers.
4. Durability and cover to reinforcement
4.1 General
(RV 7) The permissible ambient conditions, such as exposure classes and other environmental
influences (such as temperature) as well as the resulting measures are regulated in the general
building inspectorate approvals of the reinforcement kit.
4.2 Environmental conditions
(RV 4) Without additional protective measures, the bonded reinforcements may only be used in
exposure classes X0, XC1 (dry) or XC3 in accordance with DIN EN 1992-1-1, Table 4.1. In addition,
components must not be exposed to direct UV radiation (direct sun radiation or indirect sun from snow
or water reflection) or alternating or permanent penetration of moisture in the area of the
reinforcements.
(RV 5) If the component is exposed to conditions deviating from that, protective measures in
accordance with DAfStb Guideline “Schutz und Instandsetzung von Betonbauteilen” [“Protection and
repair of concrete components”] using constructions products in accordance with DIN EN 1504-2 in
combination with DIN V 18026 or DIN 18195 or other suitable protective layers shall be provided,
which will ensure that the bonded reinforcement of the component is not subjected to alternating or
permanent moisture or chemical or mechanical attacks that could damage the bond.
4.3 Requirements for durability
No additions or amendments
4.4 Analysis
No additions or amendments
4.4.1.1General
No additions or amendments
4.4.1.2 Minimum cover cmin
(RV 14) The endurance of the components should not be impaired by CFRP plates bonded in indent
cuts, even if the cuts pass into the minimum cover.
23
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
4.4.1.3 Allowance in design for deviation
No additions or amendments
5. Structural analysis
5.1 General
5.1.1 General requirements
(RV 15) Structural analysis in accordance with DIN EN 1992-1-1, Sections 5.5 and 5.6 for bending
stress is only permitted if no reduction in structural variables compared with linear elastic calculation
results in the area to be reinforced.
(RV 16) According to plan, only tensile forces may be allotted to the bonded reinforcement.
(RV 17) In the bending strain zone, the bonded steel tabs, CFRP plates and CF sheeting may be
subjected to compressive strain of Lc,max in accordance with Equation (RV 5.1). The strain shall be
determined on the assumptions of the stress-strain relations in accordance with DIN EN 1992-1-1,
Section 3.1.7.
 Lc,max  2 000 mm/m 
1
 3.5 mm/m
EL  t L
(RV 5.1)
Where:
tL
EL
thickness of steel tabs, CFRP plates or CF sheeting in mm
modulus of elasticity of steel tabs, CFRP plates or CF sheeting in mm
(RV 18) In the bending strain zone, the bonded CFRP plates may be subjected to compressive strain
of up to 3.5 mm/m in the compression zone.
(RV 19) The mean prestrain in the serviceability limit states in accordance with DIN EN 1992-1-1,
Section 7 from the effects of reinforcement shall be taken into consideration.
5.1.2 Special requirements for foundations
No additions or amendments
5.1.3 Load cases and combinations
No additions or amendments
5.1.4 Second order effects
No additions or amendments
5.2 Geometric imperfections
No additions or amendments
5.3 Idealizations and simplifications
5.3.1 Structural models for overall analysis
No additions or amendments
5.3.2 Geometric data
No additions or amendments
5.3.2.1 Effective width of flanges (all limit states)
No additions or amendments
5.3.2.2 Effective span of beams and slabs in buildings
No additions or amendments
24
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
5.4 Linear-elastic analysis
No additions or amendments
5.5 Linear elastic analysis with limited redistribution
(RV 7) Structural analysis in accordance with DIN EN 1992-1-1, Section 5.5 for bending stress is only
permitted if no reduction in structure compared with linear elastic calculation results in the area to be
reinforced.
5.6 Plastic analysis
5.6.1 General
(RV 6) Structural analysis in accordance with DIN EN 1992-1-1, Section 5.6 for bending stress is only
permitted if no reduction in structural variables compared with linear elastic calculation results in the
area to be reinforced.
5.6.2 Plastic analysis for beams, frames and slabs
No additions or amendments
5.6.3 Rotation capacity
No additions or amendments
5.6.4 Design with strut and tie models
No additions or amendments
5.7 Non-linear analysis
(RV 16) Structural analysis in accordance with DIN EN 1992-1-1, Section 5.7 is not permitted for
reinforcement using adhesive bonding.
5.8 Analysis of second order effects with axial load
5.8.1 Definitions
No additions or amendments
5.8.2 General
(RV 5) Second order effects have been taken into account in the reinforcement of supports whose top
and bottom do not shift by determining the reference angle in Section RV 6.1.4.2, if they are subjected
to a constant moment.
5.8.3 Simplified criteria for second order effects
No additions or amendments
5.8.3.1 Slenderness criterion for isolated compression members
No additions or amendments
5.8.3.2 Slenderness and effective length of isolated members
No additions or amendments
5.8.3.3 Global second order effects in buildings
No additions or amendments
5.8.4 Creep
No additions or amendments
25
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
5.8.5 Methods of analysis
No additions or amendments
5.8.6 General method
No additions or amendments
5.8.7 Method based on nominal stiffness
No additions or amendments
5.8.7.1 General
No additions or amendments
5.8.7.2 Nominal stiffness
No additions or amendments
5.8.7.3 Moment magnification factor
No additions or amendments
5.8.8 Method based on nominal curvature
No additions or amendments
5.8.8.1General
No additions or amendments
5.8.8.2 Bending moments
No additions or amendments
5.8.8.3 Curvature
No additions or amendments
5.8.9 Compression members with biaxial eccentricity
No additions or amendments
5.9 Lateral shift of slender beams
No additions or amendments
5.10 Prestressed members and structures
5.10.1General
No additions or amendments
5.10.2 Prestressing force during tensioning
No additions or amendments
5.10.2.1 Maximum stressing force
No additions or amendments
5.10.2.2 Limitation of compressive stress in concrete
No additions or amendments
5.10.2.3 Measurements
No additions or amendments
26
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
5.10.3 Prestress force
No additions or amendments
5.10.4 Immediate losses of prestress for pre-tensioning
No additions or amendments
5.10.5 Immediate losses of prestress for post-tensioning
No additions or amendments
5.10.5.1 Losses due to the instantaneous deformation of concrete
No additions or amendments
5.10.5.2 Losses due to friction
No additions or amendments
5.10.5.3 Losses at anchorage
No additions or amendments
5.10.6 Time dependent losses of prestress for pre- and post-tensioning
No additions or amendments
5.10.7 Consideration of prestress in analysis
No additions or amendments
5.10.8 Ultimate limit state
No additions or amendments
5.10.9 Effects of prestressing at serviceability limit state and limit state of fatigue
No additions or amendments
5.11 Analysis for some particular structural members
No additions or amendments
RV 5.12 Verification of shear tension at plate end
(RV1) The tensile stresses perpendicular to the adhesion surface at the end of the bending
reinforcement shall be taken into account, as this may result in so-called breakage due to shift, where
the concrete cover at the plate end detaches from the reinforcing steel. Breakage due to shift is shown
in 5.1.
Versatzbruch
Breakage due to shift
Figure RV 5.1: Schematic presentation of breakage due to shift
27
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV2) This pull-off force is considered sufficiently anchored when proof in accordance with 6.2.7 is
furnished. If this proof is not furnished, outer links in accordance with Section 9.2.6 shall be affixed to
the plate end.
6 Ultimate limit states (ULS)
6.1 Bending with or without axial force
RV 6.1.1 Reinforcement using bonded CFRP plates and CF sheeting for components subjected
primarily to bending stress
RV 6.1.1.1 Assumptions
(RV 1) A simplified analysis (Section Error! Reference source not found.) and a more
detailed analysis (Section Error! Reference source not found.) are available for the analysis
of bending reinforcement with bonded CFRP plates and CF sheeting. The simplified analysis is based
on ultimate strain that was defined on the safe side. The simplified analysis in accordance with Section
Error! Reference source not found. is considered accomplished if the listed conditions and
ultimate strain have been satisfied. In addition to these methods, there is assessment of localised
reinforcement in accordance with Section Error! Reference source not found.. The plates
may only be subjected to a force that can be anchored to the individual crack and are thus less utilised
than in the simplified analysis; however, no anchorage analysis or analysis to avoid breakage due to
shift will have to be performed.
(RV 2) In addition to proof of flexural load-bearing capacity in accordance with Section Error!
Reference source not found. or Error! Reference source not found., an analysis of
the shear resistance in accordance with Section Error! Reference source not found. and
prevention of breakage due to shift Error! Reference source not found. shall be furnished.
An analysis of prevention of breakage due to shift may be omitted if an end link in accordance with
Section Error! Reference source not found. was arranged in the construction.
(RV 3) If the bending reinforcement is to be designed for predominantly non-static loads, a fatigue
analysis in accordance with Section Error! Reference source not found. shall be conducted.
(RV 4) For all analyses except for assessment of localised reinforcement in accordance with Error!
Reference source not found., the component shall be at the ultimate limit state of cracking.
NOTE: Here the cracking moment in accordance with Error! Reference source
Error! Reference source not found. must be exceeded due to the action.
not found. or
RV 6.1.1.2 Simplified analysis
(RV 1) In the area of field moments for non-prestressed components, the analysis of bending
reinforcement may be simplified as analysis of flexural load-bearing capacity using the strain of the
plate in accordance with Equation Error! Reference source not found.. An analysis of the
bond strength transmission at the intermediate crack element is not necessary. The anchorage
analysis in accordance with Error! Reference source not found. shall be performed if one of
the following conditions has not been satisfied:

the plate extends to at least 50 mm before the support front edge;

the embedded reinforcing steel is ribbed;

the embedded reinforcing steel is not stepped;

the total plate thickness does not exceed 1.4 mm.
28
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
 Ld,max
l0

 0.5 mm/m  0.1 mm/m  h  0.04 mm/m  s  0.06 mm/m  f cm



l0
l0
 max 
 for l0  9 700 mm
  2 
3.0 mm/m 

9 700 mm 
9 700 mm 

3.0 mm/m
for l0  9 700 mm

(RV 6.1)
Where:
fcm
h
mean cylinder compressive strength of the concrete in N/mm²
total component height in mm
s
greatest reinforcing steel diameter in mm
l0
effective span in mm
(RV 2) If conducting the analysis in (RV 1), the mean cylinder compressive strength of the concrete,
which is to be substituted in Equation Error! Reference source not found., shall meet the
condition in accordance with Equation Error! Reference source not found..
f ctm, surf  0.26  f cm
2/3
(RV 6.2)
(RV 3) Within the ultimate strain of the plate, full contribution of the existing reinforcement and the
CFRP plates may be assumed in the ultimate limit state. The strain state of the existing reinforcement
of reinforced concrete components at the time of reinforcement may be determined on the assumption
of the cracked state. An analysis of longitudinal shear between tendon cross-sections shall be
conducted in accordance with DIN EN 1992-1-1, Section 6.2.4.
(RV 4) The mean modulus of elasticity values may be used for the CFRP plates or CF sheeting. The
design tensile strength of the plates fLud must not be exceeded.
RV 6.1.1.3 Detailed analysis
RV 6.1.1.3.1 Assumptions
(RV 1) The more detailed analysis shall assess the following:

Assessment of flexural load-bearing capacity using the strength of the CFRP plates or CF
sheeting in accordance with Section Error! Reference source not found.. If a simplified analysis
of bond strength transmission at the intermediate crack element is conducted in accordance with
Section Error! Reference source not found., the strain of 10 mm/m shall be complied with. The
design tensile strength of the plates fLud must not be exceeded.

Analysis of bond strength transmission at the intermediate crack element. The crack spacing in
accordance with Section Error! Reference source not found. or Error! Reference source not
found. shall be determined first. After that, both a simplified analysis of bond strength
transmission at the intermediate crack element in accordance with Section Error! Reference
source not found. may be performed or a more detailed analysis in accordance with Section
Error! Reference source not found..

Analysis of anchorage of the CFRP plate in accordance with Section Error! Reference source
not found..
(RV 2) For CFRP plates or CF sheeting, the mean modulus of elasticity values may be used for the
calculations.
RV 6.1.1.3.2 Analysis of flexural load-bearing capacity
(RV 1) Within plate strength fLud, the full contribution of the existing reinforcement and the CFRP plates
may be assumed in the ultimate limit state, provided the bond strength analysis was conducted in
accordance with Section Error! Reference source not found. and Section Error!
Reference source not found. or Error! Reference source not found.. The strain state
of the existing reinforcement of reinforced concrete components at the time of reinforcement may be
determined on the assumption of the cracked state. An analysis of longitudinal shear between tendon
cross-sections shall be conducted in accordance with DIN EN 1992-1-1, Section 6.2.4.
29
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
RV 6.1.1.3.3 Determining the crack spacing for reinforced concrete components
(RV 1) Using the simplified method, the crack spacing may be determined from 1.5 times the
dispersion length of the reinforcing steel in accordance with Equation Error! Reference source
not found..
sr  1.5  le,0
(RV 6.3)
(RV 2) The dispersion length may be obtained by Equation Error! Reference source not
found.. In Equation Error! Reference source not found., zs may be obtained by using 0.85 h
(simplified).
le,0 
M cr
z s  Fbsm
(RV 6.4)
(RV 3) The cracking moment of the cross-section may be obtained by Equation Error!
source not found. (simplified).
M cr   f l  f ctm,surf  Wc,0
Reference
(RV 6.5)
Where:
fl
= (1.6 – h/1 000)  1.0
h
total component height in mm
(RV 4) When determining the cracking moment for T-beams subject to tensile load, the effective flange
width shall be taken into account. The effective flange width for 0.5 beff,i may be obtained in
accordance with DIN EN 1992-1-1, Equation (5.7a).
(RV 5) The bond strength per length may be obtained by means of Equation Error! Reference
source not found.. The mean bond stress of the reinforcing steel may be obtained by means of
Equation Error! Reference source not found.. Only one bar with spare bar diameter shall be
used for double bars. The spare strut diameter shall be obtained in accordance with n  2  
n
Fbsm 
n
s,i
 i    f bsm
(RV 6.6)
i 1
(RV 6) The mean bond stress of the reinforcing steel dependant on the reinforcement type may be
obtained by means of Equation Error! Reference source not found.. The following shall be
used for good bond conditions vb1= vb2 =1 and for medium bond conditions vb1= 0.7 and vb2= 0.5.
  0.43  f cm 2 / 3
f bSm   vb1
 vb2  0.28  f cm
for
for
ribbed
smooth
reinforcin g steel
reinforcin g steel
(RV 6.7)
Where:
fcm
mean cylinder compressive strength in N/mm²
RV 6.1.1.3.4 Determining the crack distance for prestressed concrete components
(RV 1) The crack spacing in prestressed concrete components can be obtained as for reinforced
concrete components in accordance with RV 6.1.1.3.3, but for the cracking moment, the prestress
force in accordance with Equation Error! Reference source not found. shall be taken into
account. The prestressing steel reinforcement may be taken into account for bond strength per length
in Equation (RV 6.4), if they are in the tension zone where initial cracking occurs. Here the bond
strengths of Equation Error! Reference source not found. shall be mitigated by the values in
Table 6.2 of DIN EN 1992-1-1.
 p  Ap 

  Wc,0   p  Ap  zp
M cr    f l  f ctm,surf 
Ac 

(RV 6.8)
Where:
Ap
sectional area of the prestressing steel reinforcement
30
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Ac
sectional area of the component
p
zp
prestess of the prestressing steel at the time or reinforcement
elevation of the prestressing steel relative to the sectional centre of gravity
RV 6.1.1.3.5 Simplified analysis of plate force change at the interim crack element
(RV 1) The prestrain of the reinforcement from the reinforcement load shall be taken into account in
this analysis.
(RV 2) The strain of the plate must not exceed the maximum strain of LRd,max = 10 mm/m in any point
and the design plate strength fLud shall not be exceeded.
(RV 3) In addition to arrangements of discrete intermediate crack elements, functions for plate force
over the component length may be specified, thereby constricting place force increases (incline).
(RV 4) The intermediate crack elements should start at the maximum moment and be arranged up to
the uncracked zone offset at the respective crack spacing. The last intermediate crack element should
end in the uncracked zone, which starts after the bending crack which is closest to the point of zero
moment.
(RV 5) The plate force change from the action at each intermediate crack element shall be smaller
than the resistance plate force change of the bond.
FLEd  FLRd
(RV 6.9)
(RV 6) The plate force change at the intermediate crack element as a function of crack spacing sr is
obtained by means of Equation Error! Reference source not found..
FLEd  FLEd ( x  sr )  FLEd ( x)
(RV 6.10)
(RV 7) The resistance plate force change of the bond per intermediate crack element can be obtained
by means of Equation Error! Reference source not found.. The resistance plate force change per
intermediate crack element is constant for each intermediate crack element in a component to be
designed.
FLRd 
 L1k   L1  sr   LFk   LF  sr 4 / 3 
 BA
h
h
 sr
1/ 3
 bL
(RV 6.11)
Where:
bL
plate width in mm
L)1
LF
h
h
= 2.3
sr
h
L1k
LFk
= 0.1
= 2 000 for flat reinforced concrete components
= 0 for reinforced concrete components
distance of bending cracks in mm; the value used shall be smaller than 400 mm
component height in mm; the value used shall be greater than 100 mm
maximum bond stress in accordance with Annex RV K in N/mm²
friction bond stress in accordance with Annex RV K in N/mm²
31
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Zustand
Endv.
Lamellenkraftänderung am ZRE
State
End anchorage
Plate force change at the intermediate crack
element
Figure RV 6.1: Schematic of the analyses to be conducted on plate strain and plate force
change at the intermediate crack element
(RV 8) The plate force FLEd(x) may be obtained by means of Equation Error!
not found. in a simplified manner in accordance with Annex RV L 3.
Reference source
(RV 9) If different crack spacing values for the component to be reinforced are obtained by Equation
Error! Reference source not found., the greatest crack spacing may be used for simplified
calculation.
RV 6.1.1.3.6 Detailed analysis of plate force change at the interim crack element
(RV 1) The prestrain of the reinforcement from the reinforcement load shall be taken into account in
this analysis.
(RV 2) The proof shall be furnished for any combination of actions. The superposition principle does
not apply.
(RV 3) At each intermediate crack element, which is shown schematically in Error! Reference
source not found., proof shall be furnished that the plate force change in accordance with
Equation Error! Reference source not found. is smaller than the resistance plate force
change at the intermediate crack element in accordance with Equation Error! Reference source
not found..
FLEd  FLRd
(RV 6.12)
(RV 4) The intermediate crack elements should start at the maximum moment and be arranged up to
the uncracked zone offset at the respective crack spacing. The last intermediate crack element should
end in the uncracked zone, which starts after the bending crack which is closest to the point of zero
moment.
32
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Zustand
Endverankerung
Lamellenkraft aus der Einwirkung
Zwischenrisselement
State
End anchoring
Place force from action
Intermediate crack element
Figure RV 6.2: Schematic presentation of the intermediate crack element
(RV 5) The plate force change at the intermediate crack element as a function of crack spacing sr is
obtained by means of Equation Error! Reference source not found..
FLEd  FLEd ( x  sr )  FLEd ( x)
(RV 6.13)
(RV 6) The resistance plate force change of the bond at an intermediate crack element can be
obtained by means of Equation Error! Reference source not found. and is composed of
three parts (see also Error! Reference source not found.), one part from the base dimension
of the reinforcement bond, one part from the bond friction and one part from the component curvature.
FLRd 
ΔFLk,BL  ΔFLk,BF  ΔFLk,KF
(RV 6.14)
 BA
(RV 7) The part from the base dimension of the reinforcement bond shall be calculated as a function of
plate force FLEd at the element’s crack edge subject to the lesser load by means of Equation Error!
Reference source not found..
FLk,BL
G
D

ΔFLk,
BL  ΔFLk,BL
G
FLEd
 ΔFLk,
BL
D
FLk,

BL

2
2
 bL τ L1k sL0k ELm tL  FLEd  FLEd
D
FLEd  FLk,
BL
für
für
D
FLk,
BL
Where:
G
ΔFLk,
BL
 fbLk ( sr )  bLtL
D
FLk,
BL

D
ΔFLk,
BL
D
D
 bL τ L1k sL0k ELm tL  FLk,
BL  FLk,BL
sL0k ELmbLtL
sb
 τL1k r L
sr
4
2
2
33
 FLEd  FLud
(RV 6.15)
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
FLud
design plate breakage force
(FLud= fLuk/LL · AL) or (FLud= fLuk/LG · AL)
FLEd
plate force at the intermediate crack element’s crack edge subject to the lesser
load
fbLk (sr) characteristic bond strength as a function of crack spacing in accordance with
Equation (RV 8.9)
(RV 8) The part from the bond friction is calculated as a function of the plate base force at the
intermediate crack element and the crack spacing as well as the frictional bond stress in accordance
with Equation Error! Reference source not found..
FLk,BF






2  tL  ELm
τLFk  bL   sr 
τL1k




0
D
für FLEd  FLk,
BL
2


 τL1k  sL0k

FLEd
FLEd

 2 2


2
bL  tL  ELm  
bL  tL  ELm
 tL  ELm


D
für FLk,
BL  FLEd  FLud
(RV 6.16)
(RV 9) The part from the component curvature is obtained by means of Equation
source not found. based on concrete compression and plate strain values.
FLk,KF  sr   k 
 Lr1   cr1
h
Error! Reference
 bL
(RV 6.17)
Where:
k
Lr1
cr1
24.3 · 103 N/mm
plate strain at the crack edge subject to the lesser load
concrete strain at the crack edge subject to the lesser load
Bilinear: Gleichung
Bilinear mit Reibung: Gleichung
Krümmung: Gleichung
Bilinear: equation
Bilinear with friction: equation
Curvature: equation
Figure. RV 6.3 Resistance plate force change at the intermediate crack element
RV 6.1.1.4 Anchorage analysis
RV 6.1.1.4.1 General
(RV 1) The anchorage analysis may be conducted at the bending crack closest to the point of zero
moment, in accordance with Section Error! Reference source not found. or at any intermediate
crack element in accordance with Section Error! Reference source not found.. A link may be
34
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
arranged in the anchorage zone and an analysis conducted in accordance with Section Error!
Reference source not found..
RV 6.1.1.4.2 Anchorage at the bending crack closest to the point of zero moment
(RV 1) The analysis shall be conducted at the bending crack closest to the point of zero moment,
which is where the bending moment equals the cracking moment in accordance with Equation Error!
Reference source not found. (see also Error! Reference source not found.). The
location of the bending crack closest to the point of zero moment shall be obtained under design loads
in the ultimate limit state and without taking the magnitude of shift of tension envelope into account.
35
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Biegeriss, der dem Momentennullpunkt am
nächsten Ist
Bending crack closest to the point of zero
moment
versetzte Zugkraftlinie
Offset resistance to tension curve
Widerstand
Resistance
Zugkraftlinie Betonstahl
Resistance to tension curve of reinforcing steel
Nachweis der Zugkraftdeckung für Betonstahl
nach DIN EN 1992-1-1
Analysis of curtailment of longitudinal tension
reinforcement for reinforcing steel in accordance
with DIN EN 1992-1-1
Biegeriss, der dem Momentennullpunkt am
nächsten ist
Bending crack closest to the point of zero
moment
Nachweis der Zugkraftdeckung CFK-Lamelle
Analysis of resistance to tension of CFRP plate
36
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Zugkraftlinie
Resistance to tension curve
Nachweis der Zugkraftdeckung Betonstahl
Analysis of resistance to tension of reinforcing
steel
Figure RV 6.4: Schematic presentation of anchorage analysis for CFRP plates
(RV 2) The prestrain of the reinforcement from the reinforcement load must not be taken into account
in this analysis.
(RV 3) At the bending crack closest to the point of zero moment, the acting moment shall be smaller
than the resistance moment in accordance with Equation Error! Reference source not
found., where the magnitude of shift of tension envelope in accordance with DIN EN 1992-1-1,
Section 9.2.1.3 or DIN EN 1992-1-1, Section 9.3.1.1 shall be taken into account.
M Ed  M Rd (lbL )
(RV 6.18)
(RV 4) The resistance moment shall be calculated as a function of the strains of the reinforcement
strands by means of Equation Error! Reference source not found.. The compression zone
height and the internal lever arm may be determined at the bending crack closest to the point of zero
moment, or approximated by means of the equations in Annex RV L 1.
a
lbL   ELm  AL  zLa 
M Rd lbL    LRk
1
 BA
a
lbL   Es  As  zsa 
  sRk
1
(RV 5) The strains of the CFRP plate are calculated using Equation
not found..
a
 LRk
(lbL )
  l
 a
sin  bL    LRk,lim
   2 lbL,lim 

a
 LRk,lim

für
0  lbL  lbL,lim
für
lbL,lim  lbL
(RV 6.19)
S
Error! Reference source
(RV 6.20)
With strain as a function of maximum bond strength in accordance with Section
source not found..
a
 LRk,
lim  0.985 
Error! Reference
f bLk,max
(RV 6.21)
ELm
and the corresponding anchorage length as a function of effective bond length in accordance with
Section Error! Reference source not found..
lbL,lim  0.86  lbL,max
(RV 6.22)
(RV 6) The strains of the reinforcing steel are calculated using Equation Error! Reference
source not found. with factor N = 0.25 for ribbed reinforcing steel and N = 0 for smooth steel.
For good bond conditions, VB = 1 shall be used in Equation Error! Reference source not
found., and for medium bond conditions, VB = 0.7.
    VB   bsk  sLra lbL 
N 1/2  d a  x a 

 a
 d  xa 
 L

a
 sRk
lbL
N 1/ 2

fyk
Es
(RV 6.23)
Where:
sLra
da
dLa
xa
slippage of plate in mm in accordance with Equation Error! Reference source not
found.
effective static depth of inner reinforcement in mm
effective static depth of bonded reinforcement in mm
compression zone height in mm
(RV 7) The slippage of the plate shall be calculated in accordance with Equation
source not found..
37
Error! Reference
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
a
sLr


 l

 0,213 mm  1  cos  bL   für



lbL   
 2 lbL,lim  


a
0,213 mm  lbL  lbL,lim    LRk,lim für
0  lbL  lbL,lim
(RV 6.24)
lbL,lim  lbL
(RV 8) The bond coefficient for reinforcement embedded in concrete is obtained by means of Equation
Error! Reference source not found. with factors in accordance with Error! Reference
source not found.. Only one bar with spare bar diameter shall be used for double bars. The spare
bar diameter is obtained by N  2   .
 bsk   b1k 
 b2
f cm
(RV 6.25)
E s   b3  ELm  tL 
 b4
Where:
fcm
mean cylinder compressive strength of the concrete in N/mm²

greatest reinforcing steel diameter in mm
mean modulus of elasticity of the reinforcing steel (may be assumed to be 200 000
N/mm²) in N/mm²
mean modulus of elasticity of the plate in N/mm²
plate thickness in mm
Es
ELm
tL
Table RV 6.1: Bond coefficients for CFRP plates
Column
Line
1
2
3
4
1
Reinforcement
embedded in concrete
b1k
b2
b3
b4
2
3
Ribbed
Smooth
2.545
1.292
1.0
1.3
0.8
1.0
0.2
0.3
RV 6.1.1.4.3 Anchorage at any intermediate crack element
(RV 1) Alternatively, the anchorage analysis may be conducted at any intermediate crack element.
Here, the magnitude of shift of tension envelope in accordance with DIN EN 1992-1-1, Section 9.2.1.3
or DIN EN 1992-1-1, Section 9.3.1.1 shall be taken into account.
(RV 2) At the location of the bending crack, the concentrated plate force taking into account the
magnitude of shift of tension envelope shall be smaller than the resistance plate force in accordance
with Equation Error! Reference source not found..
FLEd  FbLRd
(RV 6.26)
(RV 3) The resistance plate force may be obtained by means of Equation Error! Reference
source not found. as a function of crack spacing in accordance with Equation Error!
Reference source not found.. The bond strength fbLd shall be obtained by means of Equation
Error! Reference source not found., with lbL to be substituted with crack spacing sr.
FbLRd  bL  tL  fbLd ( sr )
(RV 6.27)
(RV 4) In calculating the concentrated plate force, the prestrain of the reinforcement from the
reinforcement action may only be taken into account if — prior to reinforcement — the component is
already in the cracked state at the anchorage analysis point.
RV 6.1.1.4.4 Anchorage with curtailment of link
RV 6.1.1.4.4.1 General
38
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV 1) If the plate is curtailed by one or more bonded links, it only needs to be demonstrated that the
plate force at the last bonded link is smaller than the resistance force in accordance with Equation
Error! Reference source not found.. Here, the magnitude of shift of tension envelope in
accordance with DIN EN 1992-1-1, Section 9.2.1.3 or DIN EN 1992-1-1, Section 9.3.1.1 shall be taken
into account.
FbLRd  bL  tL  f bLd (lbL ) 
FL,1
 BA
(RV 6.28)
(RV 2) The bond length in Equation Error! Reference source not found. shall be obtained in
accordance with Error! Reference source not found.. The potential increase in plate force
FL,1 due to curtailment of link may be calculated in accordance with Section Error! Reference
source not found..
Figure RV 6.5: Bond length of curtailed CFRP plates
RV 6.1.1.4.4.2 Bond strength increase due to curtailment of link
Calculation of ΔFL,1 for CFRP plates or steel tabs with steel link curtailment
(RV 1) The prerequisite for application of bond strength increase due to curtailment of link is steel tab
links that were executed in accordance with Section Error! Reference source not found.
Curtailments made of CF sheeting require rules in the respective approval. If using the bond strength
increase, the flexural tension steel tabs/CFRP plates shall be arranged symmetrically to the web axis.
(RV 2) For two or more CFRP plates or steel tabs, the bond strength increase FL,1 refers to the sum
of the plate forces.
(RV 3) The increase in resistance plate tensile strength FL,1 — taking into account the crack opening
curtailment by link — shall be obtained by means of Equation Error! Reference source not
found..
t b b
FL,1  L L Lw 
120
2
f ctm, surf 

Fu ( b )
Fu ( b )  
 
 230   l 
 23    l 
1.33 
bL  bLw
bL  bLw  



(RV 6.29)
Where:
tL
bL
bLw
plate thickness [mm]
plate width [mm]
width of the curtailment link [mm]
l
l
l
= 1 for steel or CFRP cross-sections of a tab or plate
= 0.48 for two or more CFRP plate cross-sections bonded side-by-side
= 0.52 for two or more steel tab cross-sections bonded side-by-side
Fu(b)
in accordance with Equation Error! Reference source not found. [N]
(RV 4) Bond strength increase due to curtailment of link may be calculated for all values of 0.4 ≤
αb = bL / bw ≤ 0.8. For all values of αb ≤ 0.4 Δ FL,1 cannot be calculated. For all values of αb > 0.8 limit
value calculation of αb = 0.8 shall apply.
39
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV 5) If bonding several flexural strength steel tabs/CFRP plates with centre distance sL, αb may be
calculated using equivalent plate/tab width bL,eff. The equivalent width is obtained from the maximum
edge distance of the flexural tensile reinforcement in accordance with Error! Reference source
not found.. When using this effective plate/tab width, the resistance increase FL,1,eff shall be
reduced as the result from Equation Error! Reference source not found. using the ratio of
actual plate width to effective plate width in accordance with Equation Error! Reference source
not found..
FL,1  FL,1,ef f 
b
L
(RV 6.30)
bL,ef f
Figure RV 6.6: Bridging joist with several bonded CFRP plates or steel tabs
(RV 6) After determining the total link stiffness EIS,g by means of Equations Error! Reference
source not found. and Error! Reference source not found. possibly taking into account
the curtailment angle and an adhesive layer thickness tG ≥ 1 mm between the steel tab curtailments,
the crack opening curtailment Fu(αb) shall be obtained for all αb- values from 0.4 ≤ αb ≤ 0.8 by means of
Equation Error! Reference source not found.. The force needed for crack opening
curtailment shall be taken into account in the actions on the link.
 0.8   b 
   0.4 
Fu ( b )  Fu,2  
  Fu,4   b
 [N]
 0.4 
 0.4 
(RV 6.31)
Where:
b
bw
Fu,2
Fu,4
=bL/bw
joist width [mm]
Equation Error! Reference source not found. [N]
Equation Error! Reference source not found. [N]
(RV 7) The crack opening curtailment Fu,2 shall be obtained by means of Equation
Reference source not found..
Fu,2 
2  24  EI s,g,α b 0,4
(3    4   )  l2
3
3
 w1 
26 400  EI s,g, b 0, 4
11 000  l  2,4  EI s,g, b 0, 4
3
1


EI s,g, b 0.4
  0.1 [mm]
w1  w  1 
 4 583  l13  EI s,g, 0.4 
b



0.3  bw  20
bw  40
(RV 6.32)
(RV 6.33)
Where:
l1
l2
w
[N]
Error!
= 0.3 ∙ bw – 20 [mm]
= bw - 40 [mm]
= 0.35 for CFRP plates
40
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
w
= 0.25 for steel tabs
EIs,g,αb=0.4 for a curtailment angle in accordance with (RV 12)
without curtailment angle in accordance with (RV 13)
Detail
Detail
Figure RV 6.7: Bridging joist with bonded CFRP plate or steel tab for b = 0.4
(RV 8) The crack opening curtailment Fu,4 shall be obtained by means of Equation
Reference source not found..
Fu,4 
48  EI s,g, b 0.8
l4
3
 w2 
26 400  EI s,g, b  0.8
11 000  l3  2.4  EI s,g, b 0.8
3
[N]


EI s,g, b 0.8
  0.1 [mm]
w2  w  1 
3
 4 583  l3  EI s,g, 0.8 
b


Error!
(RV 6.34)
(RV 6.35)
Where:
l3
l4
w
w
EIs,g,αb=0.8
=20 + tLW [mm]
=2 ∙ l3 [mm]
= 0.35 for CFRP plates
= 0.25 for steel tabs
for a curtailment angle in accordance with (RV 12)
without curtailment angle in accordance with (RV 13)
Figure RV 6.8: Bridging joist with bonded CFRP plate or steel tab for b = 0.8
Total flexural stiffness EIS,g
(RV 9) Flexural stiffness EIS,j is composed of the link stiffness EIS and the adhesive stiffness EIG per
bond zone. As the flexural stiffness of the adhesive is very low, it will be neglected in further
41
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
calculations. The flexural stiffness EIS of a bond zone (detail A or detail B) shall be obtained by means
of Equation Error! Reference source not found..
EIS 
 E  I
S
S
 AS  zS
2

(RV 6.36)
Where:
sectional moment of inertia of a steel link [mm 4]
sectional area of a steel link [mm2]
modulus of elasticity of the steel link [N/mm 2]
distance of the centroidal axis of the sectional area of the steel to the total sectional
area [mm]
(RV 10) Calculation of flexural stiffness in zone A using two sectional areas of steel by means of
Equation Error! Reference source not found. will yield stiffness EIS,A:
IS
AS
ES
zS
Detail
Detail
Figure RV 6.9: Detail A for calculating flexural stiffness in zone A

EI S, A  2  ES  I S  AS  zS
2

(RV 6.37)
Where:
zs 
1
 t LW  0.5 [mm]
2
(RV 11) For zone B with 3 sectional areas of steel and 2 bonded joints, EIS,B shall be obtained by
means of Equation Error! Reference source not found..
Detail
Detail
Figure RV 6.10: Detail B for calculating flexural stiffness in zone B

2

EI S,B  2  ES  I S  AS  zS  ES I S
(RV 6.38)
Where:
z s  tLW  1 [mm]
(RV 12) The flexural stiffness EIS,g of the link for different stiffness values of individual link sections
shall be calculated for b = 0.4 in accordance with Equation Error! Reference source not found. and
for b = 0.8 in accordance with Equation Error! Reference source not found..
EI s,g, b 0.4  2 
EI s,g, b 0.8  2 
EI S, A  EIS, B
EI S, A  EIS, B
EIS, A  ES I S
EIS, A  ES I S
[N/mm2]
(RV 6.39)
[N/mm2]
(RV 6.40)
42
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV 13) If link sections A and B have the same stiffness, thus not requiring a curtailment angle, the
stiffness EIS,g,αb=0.4 shall be obtained by means of Equation Error! Reference source not found. and
for stiffness EIS,g,αb=0.8, the same link stiffness shall be used.
43
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
RV 6.1.1.4.5 Mechanical anchorage
(RV 1) To increase anchorage force, mechanical anchorage systems may be used for bonded CFRP
plates, assuming the respective approvals.
(RV 2) If a mechanical anchorage is used, the anchorage analysis may be conducted in accordance
with Section Error! Reference source not found. of this Guideline. This analysis shall use the
anchorage system force that can be anchored for FbLRd.
(RV 3) The mechanical anchorage forces that can be anchored can also be assumed as the maximum
plate force in flexural load-bearing capacity analysis in accordance with Section Error! Reference
source not found.. Here, the strains of the plate in the ultimate limit state in accordance with
Section Error! Reference source not found. (RV10) shall be analysed. Alternatively, an
analysis of the bond subject to infrequent combination of actions may be conducted in accordance
with Section Error! Reference source not found. (RV11).
RV 6.1.1.5 Localised reinforcements
(RV 1) For localised reinforcements, the bond length on both sides of the required reinforcement
zones shall be equivalent to at least the component thickness plus anchorage length lbL,max in
accordance with Equation Error! Reference source not found.. Only tensile forces equivalent
to the maximum resistance bond breakage force FbLRd,max at the individual crack in accordance with
Equation Error! Reference source not found. may be allocated to the adhesive bond
reinforcement.
FbLRd,max 
f bLk,max  bL  tL
(RV 6.41)
 BA
(RV 2) If the bonded reinforcement is enclosed by links, tensile forces equivalent to the resistance
bond breakage force at the individual crack may be allocated to the adhesive bond reinforcement,
taking into account the bond strength increase due to curtailment of link in accordance with Equation
Error! Reference source not found..
RV 6.1.2 Reinforcement with bonded steel tabs for components predominantly subject to
bending stress
RV 6.1.2.1 Assumptions
(RV 1) In addition to flexural load-bearing capacity analysis in accordance with Section Error!
Reference source not found. and the bond analysis in accordance with Section Error!
Reference source not found., a shear resistance analysis in accordance with Section Error!
Reference source not found. and an analysis to prevent breakage due to shift in accordance
with Section Error! Reference source not found. shall be conducted.
(RV 2) As an alternative to the bond analysis in accordance with Section Error! Reference
source not found., an analysis similar to Section RV 6.1.1.4.4 may be conducted if the resistance
force according to Equation Error! Reference source not found. is greater than the maximum
tensile force in the total system.
FbLRd  FLd,max  fLy d  AL
(RV 6.42)
RV 6.1.2.2 Analysis of flexural load-bearing capacity
(RV 1) Within the yield point of the steel tabs, the full contribution of the existing reinforcement and the
steel tabs may be assumed in the ultimate limit state, provided a bond strength analysis was
conducted. The strain state of the existing reinforcement of reinforced concrete components at the
time of adhesive bonding may be determined on the assumption of the cracked state. An analysis of
longitudinal shear between tendon cross-sections shall be conducted in accordance with DIN EN
1992-1-1, Section 6.2.4.
(RV 2) For steel tabs, a modulus of elasticity of 200 000 N/mm² may be used for calculation.
(RV 3) The strain of the steel tabs must not exceed 3 mm/m.
44
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
RV 6.1.2.3 Bond analysis
(RV 1) The analysis shall be conducted at the bending crack closest to the point of zero moment,
which is where the bending moment equals the cracking moment in accordance with Equation Error!
Reference source not found. (see also Error! Reference source not found.). The
location of the bending crack closest to the point of zero moment shall be obtained under design loads
in the ultimate limit state and without taking the magnitude of shift of tension envelope into account.
45
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Biegeriss, der dem Momentennullpunkt am
nächsten Ist
Bending crack closest to the point of zero
moment
versetzte Zugkraftlinie
Offset resistance to tension curve
Widerstand
Resistance
Zugkraftlinie Betonstahl
Resistance to tension curve of reinforcing steel
Nachweis der Zugkraftdeckung für Betonstahl
nach DIN EN 1992-1-1
Analysis of curtailment of longitudinal tension
reinforcement for reinforcing steel in accordance
with DIN EN 1992-1-1
Biegeriss, der dem Momentennullpunkt am
nächsten ist
Bending crack closest to the point of zero
moment
46
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Nachweis der Zugkraftdeckung CFK-Lamelle
Analysis of curtailment of longitudinal tension
reinforcement for CFRP plate
Zugkraftlinie
Resistance to tension curve
Nachweis der Zugkraftdeckung Betonstahl
Analysis of curtailment of longitudinal tension
reinforcement for reinforcing steel
Figure RV 6.11: Schematic presentation of anchorage analysis for steel tabs
(RV 2) The prestrain of the reinforcement from the reinforcement load must not be taken into account
in this analysis.
(RV 3) At the bending crack closest to the point of zero moment, the acting moment shall be smaller
than the resistance moment in accordance with Equation Error! Reference source not
found., where the magnitude of shift of tension envelope in accordance with DIN EN 1992-1-1,
Section 9.2.1.3 or DIN EN 1992-1-1, Section 9.3.1.1 shall be taken into account.
M Ed  M Rd (lbL )
(RV 6.43)
(RV 4) The resistance moment shall be calculated as a function of the strains of the reinforcement
strands. The compression zone height and the internal lever arm may be determined at the bending
crack closest to the point of zero moment, or approximated by means of the equations in Annex RV L
1.
a
lbL   ELm  AL  zLa 
M Rd lbL    LRk
1
 BA
a
lbL   Es  As  zsa 
  sRk
1
(RV 6) The strains of the steel tabs are obtained by means of Equation
not found..
a
 LRk
(lbL )
  l
 a
sin  bL    LRk,
lim
   2 lbL, lim 

a
 LRk,
lim

für
für
0  lbL  lbL, lim

(RV 6.44)
S
Error! Reference source
fLy k
EL
lbL, lim  lbL
With strain as a function of maximum bond strength in accordance with Section
(RV 6.45)
Error! Reference
source not found.
a
 LRk,
lim  0.906 
f bLk,max
(RV 6.46)
ELm
and the corresponding anchorage length as a function of effective bond length in accordance with
Section Error! Reference source not found..
lbL,lim  0,79  lbL,max
(RV 6.47)
(RV 7) The strains of the reinforcing steel are calculated using Equation Error! Reference
source not found. with factor N = 0.25 for ribbed reinforcing steel and N = 0 for smooth steel.
For good bond conditions, vb = 1 shall be used in Equation Error! Reference source not
found. and for medium bond conditions, vb = 0.7.
    VB   bsk  
a
 sRk
lbL
a
sLr

a 
 1/ 2  a
lbL  N   d a  x a 
 dL  x 
N 1/ 2

fyk
Es
(RV 6.48)
Where:
sLra
da
slippage of plate in mm in accordance with Equation Error! Reference source
not found.
effective static depth of inner reinforcement in mm
47
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
dLa
xa
effective static depth of bonded reinforcement in mm
compression zone height in mm
(RV 8) The slippage of the plate shall be calculated in accordance with Equation
source not found..


  l 
0.195 mm  1  0.82  cos  bL   for
2 l


s lbL   
bL,lim  



a
for
 0.195 mm  lbL  lbL,lim   LRk,lim
a
Lr
Error! Reference
0  lbL  lbL,lim
(RV 6.49)
lbL,lim  lbL
(RV 9) The bond coefficient for reinforcement embedded in concrete is obtained by means of Equation
Error! Reference source not found. with factors in accordance with Error! Reference
source not found.. Only one bar with spare bar diameter shall be used for double bars. The spare
bar diameter is obtained by N  2   .
 b2
f cm
 bsk   b1k 
(RV 6.50)
Es    b3  ELm  tL 
 b4
Where:
fcm
mean cylinder compressive strength of the concrete in N/mm²

greatest reinforcing steel diameter in mm
mean modulus of elasticity of the reinforcing steel (may be assumed to be 200,000
N/mm²) in N/mm²
mean modulus of elasticity of the plate in N/mm²
plate thickness in mm
Es
ELm
tL
Table RV 6.2: Bond coefficients for steel tabs
Column
Line
1
Reinforcement embedded
in concrete
1
b1k
b2
b3
b4
2
3
4
2
3
Ribbed
Smooth
11.9
7.7
1.2
1.8
0.7
1.0
0.5
0.7
RV 6.1.2.4 Localised reinforcements
(RV 1) For localised reinforcements, the bond length on both sides of the required reinforcement
zones shall be equivalent to at least the component thickness plus anchorage length lbL,max in
accordance with Equation Error! Reference source not found.. Only tensile forces equivalent
to the maximum resistance bond breakage force FbLRd,max at the individual crack in accordance with
Equation Error! Reference source not found. may be allocated to the adhesive bond
reinforcement.
FbLRd,max 
f bLk,max  bL  tL
(RV 6.51)
 BA
(RV 2) If the bonded reinforcement is enclosed by links, tensile forces equivalent to the resistance
bond breakage force at the individual crack may be allocated to the adhesive bond reinforcement,
taking into account the bond strength increase due to curtailment of link in accordance with Equation
Error! Reference source not found..
48
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
RV 6.1.3 Bending reinforcement using CFRP plates bonded in indent cuts
RV 6.1.3.1 Assumptions
(RV 1) In addition to a bending analysis in accordance with Section Error! Reference source
not found. and an anchorage analysis in accordance with Section Error! Reference source
not found., a shear resistance analysis in accordance with Section Error! Reference source
not found. and an analysis to prevent breakage due to shift in accordance with Section Error!
Reference source not found. shall be conducted.
(RV 2) If the bending reinforcement is to be designed for not predominantly static loads, a fatigue
analysis in accordance with Section Error! Reference source not found. shall be conducted.
RV 6.1.3.2 Analysis of flexural load-bearing capacity
(RV 1) The strain of the CFRP plate must not exceed value LRd,max according to Equation Error!
Reference source not found..
 LRd,max   ε   Lud
(RV 6.52)
Where:
ε = 0.8
(RV 2) The effective static depth dL of the CFRP plates shall be assumed in accordance with Equation
Error! Reference source not found..
b 

dL  h   ts  L 
2 

(RV 6.53)
(RV 3) The maximum tensile force with consideration of factor ε shall be obtained by means of
Equation Error! Reference source not found..
FLRd   ε 
fLuk
 LL
 AL
(RV 6.54)
(RV 4) Within the strains in accordance with DIN EN 1992-1-1, 6.1 and Section Error! Reference
source not found. (RV1) of this Guideline, the full contribution of the existing reinforcement and
the CFRP plates may be assumed in the ultimate limit state. The strain state of the existing
reinforcement of reinforced concrete components at the time of adhesive bonding may be determined
on the assumption of the cracked state.
RV 6.1.3.3 Analysis of bond load capacity, resistance to tension
(RV 1) Resistance to tension in the ultimate limit state over the entire component length shall be
assessed (Error! Reference source not found.). The resistance to tension curve taking into
account the magnitude of shift of tension envelope shall be obtained in accordance with DIN EN 19921-1, Section 9.2.1.3(2) or 9.3.1.1(4). Different strains of the individual reinforcement layers and grading
of reinforcing steel cross-sections shall be taken into account. The plate tensile force that can be
anchored by means of the bond between CFRP plate and concrete part shall be obtained by means of
Equation Error! Reference source not found. for bond lengths lb up to 115 mm, and for
longer bond lengths by means of Equation Error! Reference source not found..
Für lbL  115 mm : FbLRd  bL  bLd  4 ar  lbL  0.4  0.0015  lbL   0.95
(RV 6.55)


a 
Für lbL  115 mm : FbLRd  bL  bLd  4 ar   26.2  0.065  tanh  r   lbL  115  0.95
 70 


(RV 6.56)
Where:
FbLRd
lbL
design bond load capacity per plate in N
anchorage lengths of the plate in accordance with Error! Reference source not
found. in mm
49
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
bLd
design shear load capacity of the adhesive according to Equation Error!
Reference source not found.
bL
CFRP plate width in mm
ar
distance from the longitudinal axis of the plate to the free component edge in mm,
ar may be max. 150 mm in the calculation
(RV 2) In each cross-section of the reinforced component, it shall be ensured that the design
resistance of the component is greater than the design structural action in the reinforced state. The
partial tensile forces of the reinforcement strands shall be determined under the assumption of even
distribution of strain. Analysis of curtailment of longitudinal tension reinforcement in accordance with
Error! Reference source not found. may be conducted taking into account the relevant
provisions of EN 1992-1-1, Section 9.2.1.3(2) or 9.3.1.1(4). In particular, the analysis of resistance to
tension of existing reinforcing steel in the areas where the CFRP plates cannot be included (according
to Error! Reference source not found. by simplified approach to Point A) shall be conducted
in accordance with EN 1992-1-1.
50
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Ermittlung der Zugkraftanteile (exemplarisch)
versetzte Zugkraftlinie
Nachweis der Zugkraftdeckung Betonstahl
Zugkraftlinie Betonstahl
Nachweis der Zugkraftdeckung für Betonstahl
nach DIN EN 1992-1-1
Nachweis der Zugkraftdeckung CFK-Lamelle
Zugkraftdeckungslinie der CFK-Lamellen nach
Gin. (6.36) und (6.37)
Determining the tensile force components
(example)
Offset resistance to tension curve
Analysis of resistance to tension of reinforcing
steel
Resistance to tension curve of reinforcing steel
Analysis of resistance to tension of reinforcing
steel in accordance with DIN EN 1992-1-1
Analysis of resistance to tension of CFRP plate
Resistance to tension curve of CFRP plates
according to (6.36) and (6.37)
Figure RV 6.12: Anchorage analysis for CFRP plates bonded in indent cuts
51
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
RV 6.1.4 Column reinforcement using confinement
RV 6.1.4.1 General
(RV 1) Confinement may be used to add to shear reinforcement that is structurally required and to
allow calculation in accordance with DIN EN 1992-1-1 (see Section 9.5).
(RV 2) Confinement can be used for round columns and also to activate the multiaxial strength of the
column concrete. The corresponding calculation method is described in the following Section Error!
Reference source not found..
(RV 3) Due to the higher loads, confined compression members will shorten more than link-reinforced
compression members. The effects of these greater deformations on adjacent components may have
to be taken into account.
RV 6.1.4.2 Round supports with activation of multiaxial strength
(RV 1) To ensure the activation of multiaxial strength of the concrete, the calculated thickness tL, which
is the sheeting thickness multiplied with the number of layers shall not be less than the value obtained
by means of Equation Error! Reference source not found..
tL 
k0  D  f cm2
(RV 6.57)
EL
(RV 2) The design loadbearing capacity NRd of reinforced concrete supports with a round crosssection, rotationally symmetrical reinforcing steel longitudinal reinforcement and full-area confinement
with carbon fibre sheeting in accordance with Section Error! Reference source not found.,
and which are subjected to eccentric design forces, may be obtained by means of Equations Error!
Reference source not found. and Error! Reference source not found. for Parameters
Error! Reference source not found., Error! Reference source not found. and
Error! Reference source not found..
D  120 mm
(RV 6.58)
  40
(RV 6.59)
e0
 0.25 
D
(RV 6.60)
f cm  58 N mm2 
(RV 6.61)
(RV 3) Factors [k0] to [k9] are construction kit-specific values that can be found in the general building
inspectorate approval. Guideline values for pre-dimensioning can be found in Annex RV K.
(RV 4) The geometric variables of the confined support cross-section may be obtained according to
Error! Reference source not found..
52
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
verschmierte Betonstahlbügel- bzw.
wendelbewehrung
Umschnürung mit CFK-Gelegen
loaded reinforcing steel link or hoop
confinement using CFP sheeting
Figure RV 6.13 Cross-section of the confined reinforced concrete column
(RV 5) The loadbearing capacity of the column may be obtained by means of Equation Error!
Reference source not found.. The referenced angle  shall be obtained according to Error!
Reference source not found., which describes the tension block in the confined cross-section taking
into account time-dependent and second order effects. It shall be obtained from the combined actions
of design axial force NEd and the bending moment MEd according to first order by means of Equations
Error! Reference source not found. and Error! Reference source not found. as well as by
iteration.
NRd 
1
 LG
sin2       1

   1  f cck  Ac  1 
  c   t   f sy k  As

2      s



l2
N Rd   etot  2  1   2  bal  K  





3
1 2
D  sin      1
D sin   c   sin   t 
  1  f cck  Ac   

 f sy k  As  


 LG 3
2 

2

 s
(RV 6.62)
(RV 6.63)
Where:
l
length of the compression member
1
factor taking into account the reduction in curvature with an increase in
compressive force Nu
2
factor taking into account the geometry of the compression member and strain of
the confining reinforcement
53
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Figure RV 6.14: Schematic presentation of simplified design of sections
(RV 6) Stress-strain relations for the design of sections of the reinforced concrete support confined
with CF sheeting, links or hoops, the completeness factor 1 of the tension block may be obtained by
means of the following equation.
1  1.17  0.2 
f cck
*
f ck
(RV 6.64)
(RV 7) The characteristic compressive strength of confined concrete may be determined as a function
of the properties of the CF sheeting and the link or hoop.
f cck  f ck


 k1    E jl   juk   wy  f wy k  Δp





2
s  

 Dc  w  
2  


 
D

 

 
(RV 6.65)
(RV 8) The stiffness of the CF sheet confinement relative to column diameter D may be obtained by
means of Equation Error! Reference source not found.. This will yield a calculated thickness tL of
the confinement from the number of layers multiplied with the calculated sheeting thickness.
2  EL  tL
(RV 6.66)
D
(RV 9) To determine the characteristic strain of the confined reinforcement, the restraints of the
component r, the ambient conditions temperature and humidity T and F, the type action E and the
duration of the action in the ultimate limit state Z will be taken into account in the minuend of the
following equation. Furthermore, the subtrahend will take into account the time-dependent influences
from the previous actions that will reduce the loadbearing capacity. The longitudinal deformation of the
reinforced concrete column cc(t) from creep resulting in strain of the CF sheeting, which can be
determined in a simplified approach for shear strain  = 0.2, is deemed a state of internal stress
reducing loadbearing capacity. Factor k = 1.5 takes into account the greater spread of the creep
deformation of confined members.
E jl 
 juk  r  T  F  E  aZ   Lk  k    cc Δt 
(RV 6.67)
 r  k 2 
(RV 6.68)
 T  k3 
(RV 6.69)
 F  k 4 
(RV 6.70)
 E  k5 
(RV 6.71)
 Z  k6 
(RV 6.72)
k = 1.5
(RV 6.73)
(RV 10) The approaches to creep in confined concrete are based on the creep approach in
accordance with DIN EN 1992-1-1:2005-10, which was modified for concrete confined with CF
sheeting.
54
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
 cc Δt   k 7    c Δt     f cm    0,k 
 cp
(RV 6.74)
Ecm
(RV 11) The approach of using the factor to describe development over time c(t) allows taking into
account short residual life spans from the time of reinforcement.
 c t   1
for common reinforcement purposes
 t 1,7 
 c t   

  H  t 1,7 
(RV 6.75)
0,3
for reinforcement on components
for short residual life spans
(RV 6.76)
(RV 12) Due to full area confinement using CF sheeting, value H to describe the effect of humidity
may be selected independent of the air humidity.
 H  250
H  250   3
 35 

 f cm 
for
f cm  35 N/mm 2
(RV 6.77)
for
f cm  35 N/mm
(RV 6.78)
2
0,5
3  
(RV 6.79)
(RV 13) Factor (fcm) describes the influence of concrete compressive strength at the time of
reinforcement. The concrete compressive strength at the time of load application may differ from the
28-day strength fcm due to post-setting.
  f cm  
16,8
(RV 6.80)
f cm
(RV 14) If the creep compressive stress cp exceeds 45 % of concrete compressive strength fcm(tV0) at
the time of reinforcement tV0, non-linear effects shall be taken into account.
  e 2,7kσ 0,45
for
(RV 6.81)
k  0.45
σ
0,k
 0,k  1
kσ 
for
kσ  0.45
 cp
(RV 6.82)
(RV 6.83)
f cm
(RV 15) The creep compressive stress is obtained from the quasi-permanent actions in the
serviceability limit state, the axial force NEqp first order moment MEqp taking into account planned and
accidental eccentricity e0 and ei, using theoretical section variables Ai and Ii.
 cp 
N Eqp
Ai

M Eqp
2
Ii 
D
(RV 6.84)
Ai  Ac   s  1  As
s 
(RV 6.85)
Es
Ecm
I i  I c   s  1 
(RV 6.86)
z
j2
j s
 Asj
(RV 6.87)
(RV 16) To determine the linear elastic deformation reference value, secant modulus of elasticity Ecm
of the concrete subject to axial compressive action at the time of reinforcement tV0 in accordance with
DIN EN 1992 1-1 may be used.
(RV 17) To determine the confining effect of the reinforcing steel reinforcement, the reinforcement
degree wy is required, which shall be obtained using calculated thickness tw,eff of the loaded link or
hoop reinforcement:
 wy 
2  t w, ef f
(RV 6.88)
Dc
55
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Asw
2  sw
t w, ef f 
(RV 6.89)
(RV 18) Due to the different effective areas of the confined reinforcement made of reinforcing steel
and CF sheeting, the uneven distribution of shear compression across the cross-section shall be taken
into account.
p1  E jl   juk
p2 
(RV 6.90)


2  EL  tL   juk  t w, ef f  f wy k  p1  c
(RV 6.91)
Dc  c
2  EL  tL   juk   p1  p2   c
Δp  p1 
(RV 6.92)
Dc
(RV 19) Indicator f *ck of the simplified stress-strain relations for the design of sections may be obtained
using shear compression difference p. The second parenthesis in the following equation takes into
account that the different legs of the link or hoop reinforcement arranged at spacing s form
compression curves that will reduce the effective area of this confining reinforcement.

f ck  f ck  k1   wy
*
s 

 Dc  w 
2 
 f wy k  Δp  
D






2

(RV 6.93)
(RV 20) The referenced angles c and t describe the distribution of stress in the loaded reinforcing
steel longitudinal reinforcement in rotationally symmetrical arrangement.
0   c  1.25    0.125  1
(RV 6.94)
0   t  1.125  1.5    1
(RV 6.95)
(RV 21) First order eccentricity etot consists of planned eccentricity e0 and additional accidental
eccentricity ei in accordance with DIN EN 1992-1-1.
etot  e0  ei
(RV 6.96)
(RV 22) Factor 1 approximates the reduction in component curvature if longitudinal compressive force
increases.
1 
N balk 0.8  f cck  Ac

1
N Rk
N Rd   c
(RV 6.97)
(RV 23) Factor 2 takes into account the geometry of the compression member and strain due to
confinement.
 2  1.15  0.06     0.01  0.012   s  
 
l
1
D
(RV 6.98)
 juk
(RV 6.99)
 c2
(RV 24) The following equation for maximum curvature of the confined cross-section applies to
sections in rotationally symmetrical arrangement.
bal  2 
 cu   y k
D  Dc  2   w  s 

 cu   c2  1.75  19 

 yk 
(RV 6.100)
E jl   juk 

f cm 
(RV 6.101)
f sy k
(RV 6.102)
Es
Where:
c2
linear strain of concrete subject to unconfined compression upon reaching of
56
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
compressive strength: c2 = 0.002
(RV 25) Factor K according to DIN EN 1992-1-1, Equation (5.37) takes into account the increase in
curvature due to time-dependent creep through linear increase using effective creep ef. Effective
creep ef in Equation (5.37) shall be obtained by means of Equation Error! Reference source not
found..
ef  k7  
16,8

f cm N/mm 2

  0,k
M Eqp
(RV 6.103)
M Ed
6.2 Shear force
6.2.1 Analysis
(RV 10) In principle, shear resistance shall be in accordance with DIN EN 1992-1-1, Section 6.2. For
components with bonded bending reinforcement in accordance with RV 6.1.1 and RV 6.1, additional
requirements in accordance with Sections 6.2.3 (RV 10) through (RV 12) shall apply.
(RV 11) If a shear resistance analysis according to this section cannot be conducted, shear
reinforcement in accordance with Section Error! Reference source not found. may be
executed.
6.2.2 Members not requiring design shear reinforcement
(RV 7) When determining the design shear reinforcement VRd,C in accordance with DIN EN 1992-1-1,
Section 6.2.2, the bonded reinforcement must not be allocated to the tension reinforcement area AsL.
6.2.3 Members requiring design shear reinforcement
(RV 9) For old components, care should be taken that according to DIN EN 1992-1-1, Section 9.2.2
(4), the 3-fold area is covered by links. If this requirement has not been satisfied, the difference shall
be covered using bonded links in accordance with Section Error! Reference source not
found..
(RV 10) For components with bonded bending reinforcement in accordance with Sections RV 6.1.1
and RV 6.1.2, if the limit according to Equation Error! Reference source not found. is
exceeded, links in accordance with (RV 11) shall be executed.
VEd   sw 75 N/mm²

VRd, max
25 N/mm²
for ribbed links
(RV 6.104)
for smooth links
Where:
VEd
VRd,max
design shear force
design shear resistance in accordance with DIN EN 1992-1-1, Equation (6.9) or
(6.14)
sw
link tension analogous to DIN EN 1992-1-1, Equation (6.8) or (6.13)
(RV 11) If the limit in accordance with (RV 10) is exceeded, the resistance to tension of the CFRP
plate shall be ensured using bonded links. The shear force of the bonded links shall be designed
according to Equation Error! Reference source not found. and executed according to
Error! Reference source not found.. If the bonded links are not needed for the shear
resistance of the component, they may be designed in accordance with RV 9.2.7.1, Case 2 according
to Error! Reference source not found.. If the bonded links are also needed for the shear
resistance of the component, they shall be designed in accordance with RV 9.2.7.1, Case 1 according
to Error! Reference source not found..
VLEd
 EA L
 EA  EA  VEd
s
 max  L

 VEd  VRds
(RV 6.105)
57
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Where:
EAL
elastic stiffness of the bonded bending reinforcement
EAs
elastic stiffness of the embedded bending reinforcement
(RV 12) For all components with bending reinforcement in accordance with Error! Reference source
not found., Error! Reference source not found. and Error! Reference source not found. where
the limit value according to Equation Error! Reference source not found. is exceeded, links in
accordance with (RV 11) shall be executed.
VEd  0.33  f ck
2/3
 bw  d
(RV 6.106)
6.2.4 Shear between web and flange
(RV 8) Shear reinforcement in accordance with 6.2.4(4) of DIN EN 1992-1-1 may be augmented by
bonded reinforcement. For bonded reinforcement, only the force that can be anchored may be used
as the resistance to tension.
6.2.5 Shear transfer in joints
RV 6.2.5.1 Design of the reprofiled joint
(RV 1) For interfaces between concretes cast at different times in the bonded reinforcement area, an
analysis of the shear transfer in the joint between concretes cast at different times, depending on
location and size of the levelling area Error! Reference source not found., shall be
conducted for the following areas.
(RV 2) The shear stress of the joint shall be obtained from the change in tensile force of the bonded
reinforcement. The design longitudinal force component to be transferred by the joint shall be obtained
under the assumption of even strain distribution and taking into account the magnitude of shift of
tension envelope and prestrains of the reinforcing steel at the time of reinforcement.
(RV 3) The rules of DIN EN 1992-1-1, Section 6.2.5 shall apply to the analysis of shear at the interface
between concretes cast at different times.
(RV 4) For bonded steel tabs, bonded CFRP plates and CF sheeting, an analysis of the reprofiled joint
may be omitted if the value from the bond strength test in the adhesive pull test is used for bond stress
L1. Adhesive pull tests shall be conducted in accordance with Part 4 of this Guideline.
Table RV 6.3: Analysis for levelling between or additions to concretes cast at different times
Colu
mn
Line
1
2
3
Smallarea
1
2
Interface areas
Analysis
Large-area
Theoretical analysis of the bond
between concretes cast at
different times and adhesive pull
test
in the anchorage area of the plate to a
distance of up to 1 500 mm from the
plate end
Adhesive pull test for bond
strength
Other areas
RV 6.2.6 Shear reinforcement
(RV 1) Curtailed or non-curtailed links (Error! Reference source not found.), which are
applied to the outside of the component by adhesive bonding, may be used for shear reinforcement.
58
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
nicht geschlossener Bügel
geschlossener Bügel
vollflächige Verklebung
verklebung in Streifen
non-curtailed link
curtailed link
full-area bond
bond using strips
Figure RV 6.15: Schematic presentation of possible shear reinforcement types
(RV 2) Non-curtailed links may only be used for shear reinforcement in rectangular cross-sections. For
T-beams, links shall always be anchored in the compression zone.
(RV 3) If end links are necessary due to breakage in accordance with Section
source not found., they may be counted towards shear reinforcement.
Error! Reference
(RV 4) In departure from DIN EN 1992-1-1 6.2.1, the shear resistance of the component with shear
reinforcement may be obtained by means of Equation Error! Reference source not found..
VRd  VRd,s  VRd,Lw  Vccd  Vtd
(RV 6.107)
(RV 5) For all loadbearing components, the strut angle shall be determined in accordance with DIN EN
1992-1-1 Section 6.2.3 in combination with the National Annex.
(RV 6) An analysis of the loadbearing capacity of struts in accordance with DIN EN 1992-1-1 Equation
(6.9) shall also be furnished for shear reinforcement with the selected angle between struts.
(RV 7) For inclined links, the loadbearing capacity of the tension and compression struts may be
calculated according to DIN EN 1992-1-1, Section 6.2.3(4).
(RV 8) Additional shear resistance may be obtained by means of Equation Error! Reference source
not found.. The compression strut angle may be determined in accordance with (RV5).
VRd,Lw 
ALw
 z  fLwd  cot θ
sLw
(RV 6.108)
(RV 9) Depending on the application type, the sectional area of the shear reinforcement is calculated
according to EquationError! Reference source not found.. (Definitions see Error!
Reference source not found.)
2  t b
ALw  Lw Lw
  sLw
sLw 
 2  tLw
Verklebung in Streifen
(RV 6.109)
Vollflächi ge Verklebung
59
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV 10) The loadbearing capacity of the shear reinforcement fLwd shall be obtained by means of the
following equations, depending on the material and reinforcement type:
-
Curtailed link made of steel: Equation Error! Reference source not found.
Curtailed link made of fibre composite material: Equation Error! Reference source not
found.
Non-curtailed link made of steel: Equation Error! Reference source not found.
Non-curtailed link made of fibre composite material: Equation Error! Reference source not
found.
Curtailed link made of steel
(RV 11) The loadbearing capacity of a curtailed link made of steel is determined from the minimum of
the yield point and the stress that can be transferred by lap joints.

fLwd, GS  min f y d; fGud,Lw

(RV 6.110)
(RV 12) The stress that can be transferred by lap joints shall be obtained by means of Equations
Error! Reference source not found. through Error! Reference source not found. as
a function of plate thickness tL, modulus of elasticity EL and lap length l.
f Gud, LW 
f Guk,Lw
f Guk,Lw
(RV 6.111)
 BG


l
l
 u,Lw  2  u,Lw
f
  Guk,Lw,max lu,Lw,max 
lu,Lw,max


f
Guk,Lw,ma x

f Guk,Lw,max  1.004 

 lu,Lw  lu,Lw,max


lu,Lw  lu,Lw,max
(RV 6.112)
ELw
t Lw
(RV 6.113)
lu,Lw,max  0.121  ELw  t Lw
(RV 6.114)
Where:
ELw
tLw
modulus of elasticity of the steel tab link in N/mm²
thickness of the steel tab link in mm
Curtailed link made of fibre composite material
(RV 13) The loadbearing capacity of a curtailed link made of fibre composite material shall be obtained
by means of Equation Error! Reference source not found..
fLwd, GF  kR   Zeit  fLd
(RV 6.115)
(RV 14) Here the reduction factor kR shall be obtained as a function of curve radius rc by means of
Equation Error! Reference source not found..

r 
rc 
 rc  60 mm
0.5  c  2 
kR  
60 mm 
60 mm 

0,5
rc  60 mm

(RV 6.116)
(RV 15) The creep factor time is 0.75.
(RV 16) The construction rules in accordance with Section Error!
found. on lap length and curves shall be taken into account.
Reference source not
Non-curtailed links
(RV 17) The loadbearing capacity is determined by the minimum strength of the curtailed confinement
and the bond strength, which is obtained as a function of the geometric relations Error! Reference
source not found. obtained by means of Equations Error! Reference source not found.
through Error! Reference source not found..
60
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
fLwd  minf bLwd ; fLwd, G 
(RV 6.117)
Anzahl Bügel:
Number of links
Figure RV 6.16: Schematic presentation of the geometric situation of non-curtailed links
For d  lbL,max and lbL, max  sLw  d => f bLwd 
For d  lbL,max and sLw  lbL, max => f bLwd 
For d  lbL,max and sLw  d => fbLwd 
f bLk,max
(RV 6.118)
 BA


f bLk,max  
m Lw  1   m Lw  m Lw  1  sLw
 1 


 BA
n Lw  1  2  n Lw  1  l bL, max



fbLk,max nLw  sLw

 BA
2  lbL,max



 (RV 6.119)


(RV 6.120)
Where:
integer quotient d /sLw
integer quotient lbLmax/sLw
effective static depth
spacing of bonded links
bond strength in accordance with Section Error! Reference source not found.
effective bond length in accordance with Section Error! Reference source not
found.
(RV 18) For sLW ≥ d, the location of the inner links shall be determined and the outer links placed so
that exactly one bonded link will be placed between two inner links. The loadbearing capacity shall be
obtained by means of equation as a function of component height by means of Equations Error!
Reference source not found. to Error! Reference source not found..
nLw
mLw
d
sLw
fbLk,max
lbL,max
(RV 19) Bond strengths fbLk,max and effective bond lengths lbL,max may be determined in accordance
with Error! Reference source not found..
(RV 20) The construction rules in accordance with Section Error!
found. on lap length and curves shall be taken into account.
Reference source not
RV 6.2.7 End links to prevent breakage due to shift
(RV 1) If the concentrated shear force at the end support or deep beam end is greater than the
resistance shear force in accordance with Equation Error! Reference source not found.,
links at the plate end on the end support or deep beam end shall be provided in accordance with
Section Error! Reference source not found..
61
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction

100  s1 0,15   V
VRd,c, LE  0.75  1  19.6 
0 , 36
 Rd,c
aL


(RV 6.121)
Where:
VRd,c
in accordance with DIN EN 1992-1-1, Section 6.2.2 in combination with the
National Annex and Section 6.2.2 of this Guideline
s1
longitudinal bond of internal reinforcing steel reinforcement (in accordance with DIN
EN 1992-1-1, Section 6.2.2)
distance of plate from end support or deep beam end in mm
aL
6.3 Torsion
6.3.1 General
No additions or amendments
6.3.2 Analysis
No additions or amendments
6.3.3 Warping torsion
No additions or amendments
6.4 Punching shear
6.4.1 General
No additions or amendments
6.4.2 Loaded areas and critical sections used in analyses
No additions or amendments
6.4.3 Analysis
No additions or amendments
6.4.4 Punching shear resistance of slabs and column bases without shear reinforcement
(RV 3) When determining the punching shear resistance vRd,C in accordance with DIN EN 1992-1-1,
Section 6.4.4, the bonded reinforcement must not be allocated to the tension reinforcement area Asl.
6.4.5 Punching shear resistance of slabs and column bases with shear reinforcement
No additions or amendments
6.5 Design with strut and tie models
6.5.1 General
No additions or amendments
6.5.2 Struts
No additions or amendments
6.5.3 Ties
(RV 4) Only the force to be anchored may be used as the tie force in bonded reinforcement.
6.5.4 Design of nodes
No additions or amendments
62
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
6.6 Anchorages and laps
(RV 4) The bonded reinforcement is considered sufficiently anchored if an analysis in accordance with
Section RV 6.1.1 for bonded CFRP plates or CF sheeting, an analysis in accordance with Section
RV 6.1.2 for bonded steel tabs and in accordance with Section RV 6.1.3 for CFRP plates bonded in
indent cuts has been conducted to satisfaction.
(RV 5) The laps of bonded reinforcement shall be treated in accordance with RV 8.7.6.
6.7 Partial area loading
No additions or amendments
6.8 Fatigue analysis
6.8.1 General
(RV 3) A fatigue analysis under predominately non-static action shall be conducted for the adhesive
bond. For bonded CFRP plates, this analysis shall be conducted in accordance with Section Error!
Reference source not found., for bonded steel tabs in accordance with Section Error!
Reference source not found. and for CFRP plates bonded in indent cuts in accordance with
Section Error! Reference source not found.. Steel tabs may be used for shear
reinforcement, provided they are mechanically anchored in the compression zone. An analysis in
accordance with the respective rules and regulations shall be conducted for the mechanical
anchorage and the steel parts.
(RV 4) In addition to the fatigue analysis for the bonded reinforcement, a fatigue analysis in
accordance with DIN EN 1992-1-1, Section 6.8 shall be conducted for the concrete, reinforcing steel
and the prestressing steel. Fatigue analysis for reinforcing steel and prestressing steel in accordance
with DIN EN 1992-1-1, Section 6.8 only applies to reinforcing steels and prestressing steels in
accordance with DIN EN 1992-1-1, Sections 3.2 and 3.3. Additional tests will be required for
other/older reinforcing steels and prestressing steels that already exist in the component to be
reinforced.
6.8.2 Internal forces and stresses for fatigue verification
No additions or amendments
6.8.3 Combination of actions
No additions or amendments
6.8.4 Verification procedure for reinforcing and prestressing steel
No additions or amendments
6.8.5 Verification using damage equivalent stress range
No additions or amendments
6.8.6 Other verifications
No additions or amendments
6.8.7 Verification of concrete under compression or shear
No additions or amendments
RV 6.8.8 CFRP plates bonded to a surface
(RV 1) The CFRP plate forces under predominately non-static action shall be determined at each
intermediate crack element and at the anchorage. A fatigue analysis shall be conducted at the
respective intermediate crack element and at the anchorage. An analysis of the plate force difference
to be anchored shall be conducted in accordance with Section Error! Reference source not
found.. If this analysis cannot be conducted, the stress amplitude of the plate force to be anchored
63
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
shall be furnished in accordance with Section Error! Reference
forces may be obtained assuming a uniform strain state.
source not found.. The plate
RV 6.8.8.1 Analysis of plate force difference
(RV 1) An analysis of stress amplitude observance may be omitted if it can be demonstrated that the
elastic zone according to the law of bond stress-shift will not be exceeded under a combination of
actions in accordance with DIN EN 1992-1-1, Section 6.8.3. For this, the following condition shall be
satisfied:
FLRd,fat1 = 0.348  fctm,surf1/4  FLRd [kN] ≥ FLE,equ [kN]
Where:
fctm,surf
tensile strength of surface in N/mm²
FLRd
(RV 6.122)
design resistance to change in plate force in kN
FLE,equ plate force difference FL in accordance with Equation Error! Reference source
not found. at the respective intermediate crack element under a combination of
actions in accordance with DIN EN 1992-1-1, Section 6.8.3(3) in kN, or plate force
under a combination of actions in accordance with DIN EN 1992-1-1, Section 6.8.3
(3) at the anchorage at the bending crack closest to the point of zero moment,
taking the magnitude of shift of tension envelope in kN into account
(RV 2) The design resistance to change in plate force FLRd shall be obtained by means of Equation
Error! Reference source not found..
ΔFLRd 
FLk,BL
 BA
(RV 6.123)
Where:
FLk,BL
base bond strength at the intermediate crack element in accordance with Equation
Error! Reference source not found.
BA
bond safety factor, bonded on a surface
RV 6.8.8.2 Stress amplitude analysis at the crack edge subject to the higher load
(RV 1) If the condition in accordance with Error! Reference source not found. cannot be
satisfied, the following analysis under combination of actions in accordance with DIN EN 1992-1-1,
Section 6.8.3 shall be conducted:
ΔFLRd, f at2  ΔFLEd, f at
(RV 6.124)
(RV 2) The stress amplitude resistance analysis at the crack edge FLRd,fat2 subject to the higher load
shall be obtained as follows.
ΔFLRd, f at2    ΔFLRd
(RV 6.125)
Where:
FLRd
design resistance to change in plate force in accordance with Equation Error!
Reference source not found., where for the plate force at the crack edge
subject to the lesser load, the top load FLEdO shall be used.

Reduction to determine FLRd,fat2:
 = -c · FLEdU / FLRd + c (see Error! Reference source not found.)
c
factor taking into account the stress cycles
N
c  0,342  *
N
N
*
N

1
k
stress cycles of the action
reference value of stress cycles N* = 2 · 106
64
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
exponent for determining factor c
k = k1 = 23.2 for N < N*
k = k2 = 45.4 for N ≥ N*
k
(RV 3) The design stress amplitude from plate forces at the crack edge FLEd,fat subject to the higher
load shall be obtained as follows:
O
ΔFLEd, f at  ΔFLEd  ΔFLEd
U
(RV 6.126)
Where:
FLEdO
plate force difference FL under top load and cyclic action in accordance with DIN
EN 1992-1-1, Section 6.8.3(3) at the relevant intermediate crack element or plate
force under cyclic action in accordance with DIN EN 1992-1-1, Section 6.8.3(3) at
the anchorage at the bending crack closest to the point of zero moment, taking the
magnitude of shift of tension envelope in kN into account
FLEdU
plate force difference FL under bottom load and non-cyclic action in accordance
with DIN EN 1992-1-1, Section 6.8.3(2) at the relevant intermediate crack element
or plate force under non-cyclic action in accordance with DIN EN 1992-1-1, Section
6.8.3(2) at the anchorage at the bending crack closest to the point of zero moment,
taking the magnitude of shift of tension envelope in kN into account
bezogene Unterlast
Beiwert
Referenced bottom load
Factor
Figure RV 6.17: Diagram for determining the reduction factor 
65
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Grenzlinie der Ünterlast
bezogene Schwingbreite
Grenze des elastischen Bereichs
Bottom load limit
Reference stress amplitude
Elastic zone limit
Figure RV 6.18: Goodman-Smith diagram to show fatigue analysis 
RV 6.8.9 Bonded steel tabs
(RV 1) In addition to a bond analysis, Error! Reference source not
for the steel tab shall be conducted in accordance with DIN EN 1993-1-9.
found. a fatigue analysis
(RV 2) Forces in the steel tab under predominately non-static action shall be obtained at the bending
crack closest to the point of zero moment, taking into account the magnitude of shift of tension
envelope. At this point, the elastic zone in the law of bond stress-shift must not be exceeded under a
combination of actions in accordance with DIN EN 1992-1-1, Section 6.8.3(3). For this, the following
condition shall be satisfied:
FbLRd,fat1 = 0.348  fctm,surf1/4  fLbRd (lLb)  bL  tL ≥ FLE,equ
(RV 6.127)
Where:
fctm,surf
tensile strength of surface in N/mm²
fLbRd(lLb) design bond strength in accordance with Section Error! Reference source not
found. in N/mm²
FLE,equ
plate force at the bending crack closest to the point of zero moment, taking into
account the magnitude of shift of tension envelope in kN under a combination of
actions in accordance with DIN EN 1992-1-1, Section 6.8.3(3)
RV 6.8.10 CFRP plates bonded in indent cuts
(RV 1) With up to 2·106 stress cycles, sufficient resistance to fatigue of CFRP plates bonded in indent
cuts may be assumed if, under frequent cyclical action in accordance with DIN EN 1992-1-1, Section
6.8.3(3), the anchorage force taking into account the magnitude of shift of tension envelope does not
exceed value 0.6 FbLRd (FbLRd obtained by means of Equations Error! Reference source not
found. and Error! Reference source not found.) and the plate stress amplitude does not
exceed a value obtained by means of Equation Error! Reference source not found..
Δ L 
500 N/mm²
[N/mm²]
tL
(RV 6.128)
66
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Where:
tL
plate thickness in mm
(RV 2) In a simplified approach to Paragraph (1), the analysis may be conducted using a frequent
combination of actions in accordance with DIN EN 1992-1-1, Section 6.8.6. If this analysis can be
conducted, no further tests will be necessary.
(RV 3) Design methods for stress cycles greater than 2·106 are not covered in this Guideline.
7 Serviceability limit states (SLS)
7.1 General
(RV 4) For the purpose of serviceability limit state analysis, the stress-strain relations of the CFRP
plates may be assumed to be linear. The analysis shall be conducted on the basis of the mean
modulus of elasticity.
7.2 Limitation of stresses
Concrete, reinforcing steel and prestressing steel
(RV 8) The stress limits in accordance with DIN EN 1992-1-1 in combination with DIN EN 1992-1-1/NA
shall apply.
(RV 9) Under infrequent combination of actions in the reinforced cross-section, the strain in the
reinforcing steel may be limited to
s 
fyk
(RV 7.1)
Es
.
Bonded CFRP plates and CFRP sheeting
(RV 10) Under infrequent combination of actions in the reinforced cross-section, strain in the CFRP
plate shall be limited to
 L  0.2 %
(RV 7.2).
(RV 11) If these strains are exceeded, an analysis of the component deformation, limitation of crack
width and a detailed analysis of the bond serviceability limit state shall be conducted. Zone-wise
decoupling of the plate shall be avoided for the analysis of bond serviceability limit state.
CFRP plates bonded in indent cuts
(RV 12) Under infrequent combination of actions in the reinforced cross-section, strain in the CFRP
plate shall be limited to
 L  0.2 %
(RV 7.3).
(RV 13) If these strains are exceeded, an analysis of the component deformation and limitation of
crack width shall be conducted.
Bonded steel tabs
(RV 14) Under infrequent combination of actions, strain in the reinforced cross-section of the steel tab
shall be limited to
 s  0.8 f yk
(RV 7.4).
Column reinforcement by confinement
(RV 15) To prevent damage to the concrete structure in the serviceability limit state, the theoretically
required thickness of the confinement reinforcement tL, which is obtained from the sheeting thickness
multiplied with the number of layers, shall satisfy the following condition:
tL 



 f sy k As 
A
D
1 

  LG   F  k8   k9   f ck     cc  f ck  s   c2  Es  
   f ck 
2  EL   juk k1  
Ac



  s Ac 
Where:
67
(RV 7.5)
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
tL
D
EL
plate thickness in mm
cross-sectional diameter of the compression member in mm
modulus of elasticity of the bonded reinforcement in N/mm²
juk
characteristic strain of the confining reinforcement in accordance with Error!
Reference source not found.
LG
F
safety factor for CF sheeting
[k8]
[k9]
fck
cc
As
Ac
I*c2I
Es
fsyk
weighted safety factor for actions according to contribution of constant and variable
action on the relevant structures in the ultimate limit state
system coefficient (Annex K)
system coefficient (Annex K)
characteristic compressive strength of the concrete
reduction factor for confined concrete compressive strength in the structure
cc = 0.85
cross-section of the reinforcing steel longitudinal reinforcement
concrete cross-section
permissible concrete compression, to be determined for *c2 in accordance with DIN
EN 1992-1-1, Table 3.1. Taking into account the favourable effect of concrete
creep at low eccentricities in accordance with DIN EN 1992-1-1/NA (NCI) re 6.1
(3)P is permissible.
modulus of elasticity of the reinforcing steel longitudinal reinforcement
characteristic yield strain in the reinforcing steel longitudinal reinforcement
7.3 Crack control
7.3.1 General
(RV 11) An analysis of crack width limitation can usually be omitted. If the crack width-limiting effect of
bonded plates is to be used, the crack width may be obtained by means of Equation Error! Reference
source not found. if the crack pattern is complete.
7.3.2 Minimum reinforcement for limitation of crack width
No additions or amendments
7.3.3 Control of cracking without detailed analysis
No additions or amendments
7.3.4 Calculation of crack width
RV 7.3.5 Crack width-limiting effect of bonded plates
RV 7.3.5.1 General
(RV 1) Crack width limitation in existing structures requires that existing cracks are pressed or closed
through seasonal forced loads.
wk  scr,max   Lm   cm 
(RV 7.6)
(RV 2) The crack width is determined by twice the slip of the reinforcement.
wk  2  ssr  2  sLr
(RV 7.7)
(RV 3) Means plate strain shall be obtained by means of Equation Error! Reference source not
found. and the mean concrete strain may be obtained by means of Equation Error! Reference
source not found. or, in a simplified approach, it can be assumed to be zero.

 Lm   LII L  0,5  f ct,ef f  Act,ef f  
L2
 Es As 
EL AL  L2




(RV 7.8)
68
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
 cm  0,4 
f ct,ef f
(RV 7.9)
Ec
Where:
Act,eff
(sectional) area of zone of concrete section in which reinforcement is effective Act,eff
is the concrete area around the tension reinforcement with height hc,ef, where hc,ef is
the minimum of [2.5(h – ds); (h – x)/3; h/2] (see DIN EN 1992-1-1, Figure 7.1)
L
ratio of bond strength of the bonded reinforcement to embedded reinforcement in
accordance with Equation Error! Reference source not found.
mean effective tensile strength of the concrete that can be expected when cracking
occurs (see also DIN EN 1992-1-1, Section 7.3.2)
fct,eff
LII
L
strain of the plate in the crack using Bernoulli’s theory on beams assumptions
factor taking into account the different elastic stiffness values and bond strengths in
accordance with Equation Error! Reference source not found.; without
reinforcing steel reinforcement, this factor is 1.0.
(RV 4) The maximum crack spacing scr,max may be obtained by means of Equation Error!
Reference source not found.. The mean bond stress Lm of the bonded reinforcement may be
determined in accordance with Section RV 7.3.5.2 or RV 7.3.5.3, depending on the reinforcement
type.
scr,max 
Ac,ef f  f ct,ef f
2   Lm

kLb  EL  tL  L2
(RV 7.10)
Es As  EL AL  L2
(RV 5) The ratio of bond strength of the bonded reinforcement to embedded reinforcement may be
obtained by means of Equation Error! Reference source not found. as a function of mean bond
stresses according to Equation Error! Reference source not found. and Section RV 7.3.5.2 or RV
7.3.5.3. Factor L for taking into account the different elastic stiffnesses and bond strengths may be
obtained by means of Equation Error! Reference source not found. using factor L obtained by
Equation Error! Reference source not found..
Es  d s
 Lm

 sm kLb  EL  tL
L 
(RV 7.11)
L 
 Lr 2  L2

 sr L2  1
(RV 7.12)
L 
1  EL AL /Es As    L
1  EL AL / Es As    L
(RV 7.13)
(RV 6) The mean bond stresses of reinforcement embedded in concrete may be obtained by means of
Equations Error! Reference source not found.. In Equation Error! Reference source not found.
factor s shall be obtained from Error! Reference source not found.. Factor kseff in Equation Error!
Reference source not found. shall be obtained by means of value ks from Error! Reference source
not found. and factor kt according to Equation Error! Reference source not found. taking into
account bond creep obtained by means of Equation Error! Reference source not found..
 sm 
ks,ef f f cm
ks,ef f 
s  1
1
1  kt α
s
αs
 ssr
[N/mm²]
(RV 7.14)
(RV 7.15)
ks
kt  (1  10  t )0.08  1
(RV 7.16)
Where:
t
residual life span in hours
fcm
mean cylinder compressive strength in N/mm²
69
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
slip of reinforcing steel in accordance with Equation
ssr
Error! Reference source
not found.
Table RV 7.1: Bond factors of embedded reinforcement for calculation of crack width
Column
Line
1
2
1
Bond conditions
s
ks
3
2
Ribbed bars
Good
Medium
0.25
0.25
3
Smooth bars
Good
Medium
0
0
2
0.25
1
0.13
RV 7.3.5.2 CFRP plates bonded in indent cuts
(RV 1) The mean bond stresses of CFRP plates bonded in indent cuts may be obtained by means of
Equation Error! Reference source not found.. In Equation Error! Reference source not found. the
factor L shall be obtained by means of Equation Error! Reference source not found. from onesided adhesive thickness tG. Factor kLeff in Equation Error! Reference source not found. shall be
obtained by means of Equations Error! Reference source not found. to Error! Reference source
not found.
 Lm 
kL,ef f
L  1
αL
 sLr
 1  L 
(RV 7.17)
 L  0.38  tG  0.11  0.31
kL,ef f 
1
1  kt 
L
(RV 7.18)
(RV 7.19)
kL
kL  5αL   bGk
(RV 7.20)
k t  (1  10  t ) 0.14  1
(RV 7.21)
kLb  2
(RV 7.22)
Where:
residual life span in hours
t
bGk
characteristic bond strength at adhesive failure according to Equation Error!
Reference source not found. in N/mm²
tG
adhesive thickness in mm
sLr
plate slip obtained by means of Equation Error! Reference source not found.
(RV 2) For the crack width-limiting effect of plates bonded in indent cuts, the plate spacing must not
exceed 200 mm.
RV 7.3.5.3 Adhesive bonding
(RV 1) The mean bond stresses are assumed to be constant for adhesive bonding and shall be
obtained by means of Equation Error! Reference source not found.. The marginal values sL0k
andL1k were taken from Annex RV K or are regulated by general building inspectorate approvals.
 L1k

 sLr
für 0  sLr  sL1k

2  sL1k

(RV 7.23)
 Lm  
2
 L1k  sLr  2  sLr  sL0k  sL1k  sL0k für s  s  s
L1k
Lr
L0k

2  sLr  sL1k  sL0k 


sL1k  2,5 

50 mm
  L1k
Ecm
(RV 7.24)
kLb  4
(RV 7.25)
Where:
sLr
plate slip obtained by means of Equation Error! Reference source not found.
70
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV 2) For the crack width-limiting effect of the bonded CFRP plates, centre distance aL shall not
exceed the specifications in RV 8.2.1.1. Likewise, centre distance aL  3∙bL shall be observed.
(RV 3) To apply the crack width-limiting effect of adhesive bonding, the condition of Equation
(RV 7.26) must be satisfied.
Es  s
 32
EL  tL
(RV 7.26)
7.4 Limitation of deformations
7.4.1 General
(RV 7) The limit values for deformations in accordance with DIN EN 1992-1-1, Section 7.4.1 shall be
observed even after the reinforcement measures.
(RV 8) The deformations may be calculated in accordance with DIN EN 1992-1-1, Section 7.4.3. As a
rule, deformation analysis without direct calculation in accordance with DIN EN 1992-1-1, Section
7.4.2 must not be used for reinforced components.
7.4.2 Cases where calculations may be omitted
(RV 8) As a rule, deformation analysis without direct calculation in accordance with DIN EN 1992-1-1,
Section 7.4.2 must not be used for reinforced components.
7.4.3 Checking deflections by calculation
(RV 9) In calculating the deflections in accordance with DIN EN 1992-1-1, Section 7.4.3, the effect of
the plate may be taken into account in the deflection parameters .
(RV 10) Deflections at the time of reinforcement shall also be taken into account.
8 Detailing of reinforcement and prestressing tendons —
general
8.1 General
(RV 5) The general reinforcement rules in accordance with DIN EN 1992-1-1 in combination
with DIN EN 1992-1-1/NA shall apply, unless stipulated otherwise.
8.2 Spacing of reinforcing steel bars
RV 8.2.1 Spacing of plates
RV 8.2.1.1 Bending reinforcement using steel tabs, CFRP plates and CF sheeting bonded to a
surface
(RV 1) The following applies to the centre distance aL of tension plates:
max aL
 0.2 times effective span
 5 x T-beam thickness
 0.4 x cantilever length
(RV 2) The edge distance of the plate’s longitudinal edge shall be at least equivalent to the nominal
concrete cover cnom of the embedded reinforcement.
RV 8.2.1.2 Bending reinforcement using CFRP plates bonded in indent cuts
RV 8.2.1.2.1 Edge distances
(RV 1) A minimum distance ar to the free component shall be maintained, which shall be equivalent to
the greater of Equations Error! Reference source not found. and Error! Reference
source not found..
71
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
ar  2∙bL
(RV 8.1)
ar  dg
Where:
(RV 8.2)
CFRP plate width
maximum particle size
bL
dg
(RV 2) To arrange CFRP plates on both sides of a free edge in accordance with Error! Reference
source not found., a minimum distance from one of the plates in accordance with Equation
Error! Reference source not found. shall be maintained.
ar  4∙bL
(RV 8.3)
2 bL
4 bL
Figure RV 8.1: Edge distances in arrangement of plate on both sides of an edge
(RV 3) For plates and beams that are not equipped with tab links for absorbing deflection forces in the
curvature zone of the CFRP plates, a minimum edge distance of 150 mm in the direction of centre of
curvature shall be maintained. For other cases, Sections (RV1) and (RV2) shall apply. The curvature
radius of bonded plates shall be at least 2 m.
RV 8.2.1.2.2 Centre distance
(RV 1) To following applies to the minimum centre distance aL of tension plates:
aL  dg
(RV 8.4)
for as > 2∙ the following applies: aL  bL
Where:
(RV 8.5)

diameter of the reinforcing steel bond running parallel to the CFRP plates
as
clear space between two bars of the reinforcement that is parallel to the CFRP
plates
dg
maximum particle size
(RV 2) For clear spaces in the reinforcing steel bond of less than 2ds, the minimum centre distance for
tension plates according to Error! Reference source not found. shall be maintained.
72
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
Achsabstand der CFK-Lamellen
lichter Abstand der parallel zu den CFK-Lamellen
verlaufenden Bewehrung
Durchmesser der parallel zu den CFK-Lamellen
verlaufenden Bewehrung
Centre distance of CFRP plates
Clear space of that reinforcement that is parallel
to the CFRP plates
Diameter of reinforcement that is parallel to the
CFRP plates
Figure RV 8.2: Minimum centre distance of tension plates
(RV 3) The following applies to the maximum centre distance aL of tension plates:
aL  0.2 l0
(RV 8.6)
aL  4 h
Where:
(RV 8.7)
l0
h
effective span in mm, for cantilever arms: l0 = 2 lk
component thickness in mm
8.3 Bending of steel
RV 8.3.1 Bending of the bonded reinforcement
(RV 1) Steel tabs for link reinforcement may be pre-bent at the factory.
(RV 2) Recently manufactured CFRP plates may not planned to be arranged at a radius that is less
than 1 000 times their thickness.
(RV 3) CF sheeting may be arranged bent, provided the curve radius of the concrete cover is at least
25 mm.
8.4 Anchorage of longitudinal reinforcement
8.4.1 General
No additions or amendments
8.4.2 Ultimate bond stress
No additions or amendments
8.4.3 Basic anchorage length
No additions or amendments
8.4.4 Design anchorage length
No additions or amendments
73
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
RV 8.4.5 Anchorage of the bonded reinforcement
(RV 1) For anchorage of CFRP plates bonded in indent cuts, the analysis in accordance with Section
Error! Reference source not found. shall be conducted.
(RV 2) For anchorage of bonded CFRP plates and CF sheeting, bending reinforcement analysis in
accordance with Section Error! Reference source not found. shall be observed. For bonded
links, Section Error! Reference source not found. and Error! Reference source not
found. should be observed.
(RV 3) For anchorage of bonded steel tabs, bending reinforcement analysis in accordance with
Section Error! Reference source not found. shall be observed. For bonded links, Sections
Error! Reference source not found. and Error! Reference source not found. should
be observed.
RV 8.4.6 Base dimension of the adhesive bond for reinforcement bonded to a surface
(RV 1) The bond of adhesive reinforcement is described by the differential equation of the shifting
bond. For the bond stress-slip relations, a bilinear bond method is used for flat elements, described by
three parameters sL0k, L1k and LRk. The parameters can be found in Annex RV K or may be regulated
by general building inspectorate approvals.
(RV 2) The maximum resistance to plate tension at the individual crack shall be obtained by means of
Equation Error! Reference source not found..
ELm  sL0k   L1k
tL
fbLk,max 
(RV 8.8)


l
l
 f bLk,max  bL  2  bL
fbLk (lbL )  
lbL,max 
lbL,max

fbLk,max


 lbL  lbL,max


lbL  lbL,max
(RV 8.9)
fbLk (lbL )
fbLd (lbL ) 
(RV 8.10)
 BA
(RV 3) The corresponding maximum effective bond length of the adhesive bond can be obtained by
means of Equation Error! Reference source not found. where Lb = 1.128.
lbL,max 
2
Lb

ELm  tL  sL0k
(RV 8.11)
 L1k
RV 8.4.7 Base dimension of the adhesive bond in indent cuts
(RV 1) The bond strength of adhesive bond in indent cuts can be obtained by means of Equation
Error! Reference source not found. from the minimum bond strength of concrete and
adhesive.
 bLd 
1
 BE


 min bGk bG


 bck bc
(RV 8.12)
Bond stress of the adhesive according to Equation Error!
 bGk  ksy s   2  fGtk  2 

f
2
Gtk

 fGck  fGtk  fGck   fGtk

and bond stress of the concrete according to Equation
 bck  kbck  fcm
Reference source not found.
(RV 8.13)
Error! Reference source not found..
(RV 8.14)
Where:
fcm
ksys
mean cylinder compressive strength of the concrete in N/mm²
product-specific system factor for adhesive bond failure in accordance with general
74
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
kbck
building inspectorate approvals [-]
ksys = 0.6 may be used for predimensioning
product-specific system factor for concrete bond failure in accordance with general
building inspectorate approvals [-]
kbck = 4.5 may be used for predimensioning
bG
product-specific system factor for endurance behaviour of adhesive bond in
accordance with general building inspectorate approvals [-]
bG = 0.5 may be used for predimensioning.
bC
product-specific system factor for endurance behaviour of concrete in accordance
with general building inspectorate approvals [-]
bc = 0.9 may be used for predimensioning.
8.5 Anchorage of links and shear reinforcement
No additions or amendments
8.6 Anchorage by welded bars
No additions or amendments
8.7 Laps and mechanical couplers
8.7.1 General
No additions or amendments
8.7.2 Laps
No additions or amendments
8.7.3 Lap length
No additions or amendments
8.7.4 Transverse reinforcement in the lap zone
No additions or amendments
8.7.4.1 Transverse reinforcement for bars in tension
No additions or amendments
8.7.4.2 Transverse reinforcement for bars permanently in compression
No additions or amendments
8.7.5 Laps for welded mesh fabrics made with ribbed wires
No additions or amendments
8.7.5.1 Laps of the main reinforcement
No additions or amendments
8.7.5.2 Laps of secondary or distribution reinforcement
No additions or amendments
RV 8.7.6 Plate lap joints
RV 8.7.6.1 Bonded CFRP plates
(RV 1) Bonded plates may be joined by lapping if the lap joint is in an area where the existing plate
tensile strength does not exceed the maximum force transferable in the lap joint in accordance with
Equation Error! Reference source not found.. The joint between plates may be executed as
75
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
a lap joint bonded by adhesive. The lap length may be obtained by means of Equation
Reference source not found..
Füd,max 
0,753
 BG
 bL  ELm  tL
Error!
(RV 8.15)
lü,max  0,161  ELm  tL
(RV 8.16)
(RV 2) Bonded plate joints are not permissible for predominately non-static action.
RV 8.7.6.2 CF sheeting bonded to a surface
(RV 1) Bonded CF sheeting may only be joined by lap under the following conditions: The lap joint
shall be in an area where the existing sheeting tensile strength does not exceed 60 % of the limit
tensile strength of the sheeting.
(RV 2) The sheeting layers of joined sections shall overlap each other at 250 mm.
(RV 3) Bonded sheeting joints are not permissible for predominately non-static action.
RV 8.7.6.3 Bonded steel tabs
(RV 1) Bonded steel tabs may be joined by lapping if the lap joint is in an area where the existing plate
tensile strength does not exceed the maximum force transferable in the lap joint in accordance with
Equation Error! Reference source not found.. The connection between the tab and the
overlap panel of the same thickness tL shall be executed by fillet welds designed in accordance with
DIN EN 1993-1-8 prior to adhesive bonding of the tab and arranged on the side of increasing tensile
force. On the side of decreasing tensile force, the lap panel may be bonded onto the tab. The lap
length may be obtained by means of Equation Error! Reference source not found..
Füd,max 
1.004
 BG
 bL  ELm  tL
(RV 8.17)
lü,max  0.121 ELm  tL
(RV 8.18)
(RV 2) Bonded plate joints are not permissible for predominately non-static action.
8.8 Additional rules for large diameter bars
No additions or amendments
8.9 Bundled bars
8.9.1 General
No additions or amendments
8.9.2 Anchorage of bundles of bars
No additions or amendments
8.9.3 Lapping bundles of bars
No additions or amendments
8.10 Prestressing tendons
8.10.1 Arrangement of prestressing tendons and ducts
No additions or amendments
8.10.1.1 General
No additions or amendments
76
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
8.10.1.2 Pre-tensioned members
No additions or amendments
8.10.1.3 Post-tension ducts
No additions or amendments
8.10.2 Anchorage of pre-tensioned tendons
No additions or amendments
8.10.2.1 General
No additions or amendments
8.10.2.2 Transfer of prestress
No additions or amendments
8.10.2.3 Anchorage of tendons for the ultimate limit states
No additions or amendments
8.10.3 Anchorage zones of post-tensioned or unbonded members
No additions or amendments
8.10.4 Anchorages and couplers for prestressing tendons
No additions or amendments
8.10.5 Deviators
No additions or amendments
9 Detailing arrangements for structural members
9.1 General
No additions or amendments
9.2 Beams
9.2.1 Longitudinal reinforcement
No additions or amendments
9.2.1.1 Maximum and minimum reinforcement areas
No additions or amendments
9.2.1.2 Other detailing arrangements
No additions or amendments
9.2.1.3 Curtailment of longitudinal tension reinforcement
(RV 5) The offset tensile force and resistance to tension curves for the ultimate limit state shall be
shown for each component. Cutting into the offset tensile strength curve is not permissible.
9.2.1.4 Anchorage of bottom reinforcement at an end support
No additions or amendments
9.2.1.5 Anchorage of bottom reinforcement at intermediate supports
No additions or amendments
77
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
9.2.2 Shear reinforcement
(RV 9) Bonding by adhesive as shear reinforcement is not permissible.
9.2.3 Torsion reinforcement
No additions or amendments
9.2.4 Surface reinforcement
No additions or amendments
9.2.5 Indirect supports
No additions or amendments
RV 9.2.6 Links of the bonded reinforcement
(RV 1) The anchorage zone of the bending reinforcement shall be curtailed with a tab link made of
steel or bonded sheeting if an analysis in accordance with Section Error! Reference source not
found. cannot be carried out. The link must not be located more than 50 mm from the plate end
(Error! Reference source not found.).
Endverbügelung
Biegeverstärkung
End link
Bending reinforcement
Figure RV 9.1: Arrangement of the tab link or CF sheeting at the plate end
(RV 2) The tab link in accordance with Section (RV1) shall be designed for the design concentrated
tensile force in accordance with Equation Error! Reference source not found..
*
FLwEd  FLEd
 tanθ
(RV 9.1)
(RV 3) For bonded CFRP plates, CF sheeting and steel tabs, FLd* is equivalent to the maximum bond
force in accordance with Equation Error! Reference source not found..
*
FLEd
 fbLk,max  bL  tL
(RV 9.2)
(RV 4) In CFRP plates bonded in indent cuts, FLd* is equivalent to the design tensile strength of the
anchored CFRP plates at their end, which is to be calculated under the assumption of even strain
distribution and a rigid bond as well as taking into account of the magnitude of shift of tension
envelope.
(RV 5) In Equation Error! Reference source not found.,  corresponds to the angle
underlying the shear force analysis in accordance with Section Error! Reference source
found.or Error! Reference source not found..
not
(RV 6) The link anchorage may be executed by adhesive bonding or anchorage in the compressive
zone. The tab link to be arranged in the anchorage zone may be attributed to the steel tabs absorbing
the shear force, provided it is in accordance with Section Error! Reference source not
found..
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV 7) Anchorage of links in the compression zone may be foregone if the tensile force allocated to
the link can be transmitted to the concrete component via adhesive bond. Analysis in accordance with
Equation Error! Reference source not found..
FLwEd  2  FbLwRd
(RV 9.3)
(RV 8) The bond break-off force per link leg FbLwRd shall be calculated by means of Equation Error!
Reference source not found.. The links shall be bonded by adhesive over the entire web
height. Only half of the existing adhesive bonding length may be used as bond length lbL. Bond
strength fbLd(lbL) shall be determined in accordance with Section RV 8.4.6.
FbLwRd  bLw  tLw  fbLd (lbL )
(RV 9.4)
(RV 9) If links in accordance with Section 6.2.3 (RV 10), (RV 11) and (RV 12) are required that are not
needed for the shear resistance of the component, anchorage in the compression zone can be
foregone. Links shall be designed in accordance with Equation Error! Reference source not found..
VLEd 
2  FbLwRd
 z  cot θ
sLw
(RV 9.5)
Where:
FbLwRd
in accordance with Section (RV 8) and Equation Error! Reference source not
found.
cot 
sLw
z
compression strut incline of shear force design
spacing of bonded links
inner lever arm of component, may be assumed to be 0.9 · d
RV 9.2.7 Execution of bonded links
RV 9.2.7.1 General
(RV 1) In general, one distinguishes between three cases of bonded links:

Case 1: The bonded link is needed for shear force design. The bonded link shall be designed in
accordance with Section Error! Reference source not found.. If tab links are executed as
curtailed links in accordance with Section Error! Reference source not found., the centre
distance of adjacent tab links must not be greater than the beam height. If tab links are executed
as non-curtailed links in accordance with Section Error! Reference source not found., the
centre distance of adjacent tab links must not be greater than half the beam height. Links
according to case 1 may be used as end links in accordance with Section Error! Reference
source not found.. Additionally, with this link, an increase in bond strength in accordance with
Section Error! Reference source not found. may be assumed. Here, the effects from shear
force according to Section Error! Reference source not found., the effects from linkage
according to Section Error! Reference source not found. and the effects from crack opening
force Fu (b) according to Equation Error! Reference source not found. shall be superposed.

Case 2: The bonded link is used as end link or is necessary due to linking in accordance with
Section 6.2.3 (RV 10), (RV 11) and (RV 12). This link shall be designed and arranged in
accordance with Section Error! Reference source not found.. It is not necessary to anchor this
link in the compression zone. Additionally, with this link, an increase in bond strength in
accordance with Section Error! Reference source not found. may be assumed. Here, the
effects from shear force according to Section Error! Reference source not found. shall be
superposed with the effects from crack opening force Fu (b) according to Equation Error!
Reference source not found..

Case 3: Due to an increase in bond strength, the bonded link is arranged in accordance with
Section Error! Reference source not found.. This link may be arranged free and shall be
designed for crack opening force Fu (b) in accordance with Equation Error! Reference source
not found.. Anchorage may be executed in accordance with Section Error! Reference source
not found. (RV8) or additional anchorage elements in the compression zone.
79
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
RV 9.2.7.2 Steel tab links
(RV 1) The tab links shall be arranged perpendicular to the component axis and bonded by adhesive
over the entire web height. Here the centre distance must not exceed component height h.
(RV 2) If they are anchored in the compression zone, the tensile force to be anchored may be reduced
to 2/3 of its calculated value for predominantly static actions.
(RV 3) For components that are not accessible from above, anchorage of the tab links in the
compression zone may be executed using approved adhesive anchors.
(RV 4) With anchorage by adhesive bond, the tab links shall be protected against falling (e.g. by
means of dowels) in case of fire.
(RV 5) Bonded tabs may be joined by lapping in accordance with Error! Reference source not
found., if the existing tab force does not exceed the maximum force according to Equation Error!
Reference source not found. that can be transmitted in the lap joint. The lap length may be
obtained by means of Equation Error! Reference source not found..
Füd,max 
1.004
 BG
 bL  ELm  t L
(RV 9.6)
lü,max  0.121  ELm  t L
(RV 9.7)
(RV 6) In a lap joint in accordance with (RV5) or Error! Reference source not found., the leg
length of the curtailment links ls,U shall be bw – 20 [mm]. The leg length of the curtailment angle
ls,A shall equal (bw – bL)/2 + 20 [mm] if bond strength increase due to the link according to Section
Error! Reference source not found. is assumed. Otherwise the leg length of the curtailment
angle shall equal ls,A = 0.5 lü,max.
(RV 7) Bonded tab joints are not permissible for predominately non-static action.
Figure RV 9.2: Construction of a bonded link lap joint
RV 9.2.7.3 CF sheeting
(RV 1) The CF sheeting shall be laminated over the entire web with the fibres perpendicular to the
component axis.
(RV 2) The layers may be joined individually using a lap length of 250 mm.
(RV 3) The centre distance of the shear CF sheeting must not exceed the component height h.
(RV 4) The corners of the webs shall be curved at a minimum r ≥ 25 mm.
9.3 Solid slabs
9.3.1 Flexural reinforcement
9.3.1.1 General
(RV 6) The offset tensile force and resistance to tension curves for the ultimate limit state shall be
shown for each component. Cutting into the offset tensile strength curve is not permissible.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
(RV 7) For slabs, shear reinforcement in accordance with DIN EN 1992-1-1, Section 9.3.1.1 must be in
place. Missing shear reinforcement may be added using adhesive bonding reinforcement. For design
purposes, the bond break force in accordance with Section Error! Reference source not
found. or Error! Reference source not found. shall be used as the maximum plate force.
(RV 8) For one-way spanning slabs, 20 % of the existing steel reinforcement is also sufficient for the
shear reinforcement of reinforced components.
(RV 9) For slabs with flexible support, at least half of the required field reinforcement should be routed
through the support and anchored there in accordance with DIN EN 1992-1-1, Section 8.4.4. The
magnitude of shift of tension envelope aL of the T-beams without shear reinforcement is assumed to
be 1.0d. If less than 50 % of the required field reinforcement of reinforcement slabs is anchored in the
support, the magnitude of shift of tension envelope shall be increased by factor 0.5(erf As,field/vorh
As,support) ≥ 1.0. Regardless of this, in reinforced components, at least 25 % of As,field shall be routed
through the support.
(RV 10) For the analysis of plate or steel tab anchorage in accordance with RV 6.1.1.4 and RV 6.1.2.3,
magnitude of shift of tension envelope may be determined for 0.5 h in departure from DIN EN 1992-11, Section 9.3.1.1 (4). For anchorage of the longitudinal reinforcement, the magnitude of shift of
tension envelope shall be selected in accordance with DIN EN 1992-1-1, Section 9.3.1.1 (4).
9.3.1.2 Reinforcement in slabs near supports
No additions or amendments
9.3.1.3 Corner reinforcement
No additions or amendments
9.3.1.4 Reinforcement at the free edges
No additions or amendments
9.3.2 Shear reinforcement
No additions or amendments
9.4 Flat slabs
9.4.1 Slab at internal columns
No additions or amendments
9.4.2 Slab at edge columns
No additions or amendments
9.4.3 Punching shear reinforcement
No additions or amendments
9.5 Columns
9.5.1 General
9.5.2 Longitudinal reinforcement
9.5.3 Shear reinforcement
(RV 7) In non-reinforced columns with insufficient shear reinforcement in accordance with DIN EN
1992-1-1, Section 9.5.3, missing shear reinforcement may be added in the form of CF sheeting
bonded by adhesive. It shall be bonded as a minimum of two wrapped layers. The necessary sheeting
cross-section may be obtained by means of Equation Error! Reference source not found..
Construction notes according to RV 9.5.4 shall be taken into consideration.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
AL,erf 
As,erf  f y d
(RV 9.8)
0,9  fLwd, GF
Where:
As,erf
fyd
fLwd,GF
required shear reinforcement in accordance with DIN EN 1992-1-1, Section 9.5.3
design yield strength of the longitudinal reinforcement
design strength of the sheeting according to Equation Error! Reference source
not found.
RV 9.5.4 Column reinforcement
(RV 1) For column reinforcement in accordance with Section Error! Reference source not found.,
the columns shall be wrapped completely and over the entire column height in CF sheeting bonded by
adhesive according to Error! Reference source not found..
Vollflächige Umschnürung über die gesamte
Stützenhöhe
Complete confinement over the entire column
height
Figure RV 9.3Arrangement of CF sheeting
(RV2) The minimum lap length of CF sheeting is 250 mm.
(RV 3) The corners of rectangular columns shall be curved at a minimum r ≥ 25 mm.
9.6 Walls
9.6.1 General
No additions or amendments
9.6.2 Vertical reinforcement
No additions or amendments
9.6.3 Horizontal reinforcement
No additions or amendments
9.6.4 Shear reinforcement
No additions or amendments
9.7 Deep beams
No additions or amendments
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
9.8 Foundations
9.8.1 Pile caps
No additions or amendments
9.8.2 Column and wall footings
No additions or amendments
9.8.2.1 General
No additions or amendments
9.8.2.2 Anchorage of bars
No additions or amendments
9.8.3 Tie beams
No additions or amendments
9.8.4 Column footing on rock
No additions or amendments
9.8.5 Bored piles
No additions or amendments
9.9 Regions with discontinuity in geometry or action (D regions)
No additions or amendments
9.10 Limitation of damage due to accidental actions
9.10.1 General
(RV 7) Steel tabs and links shall be protected against falling (e.g. by means of dowels) in case of fire.
9.10.2 Proportioning of ties
No additions or amendments
9.10.2.1 General
No additions or amendments
9.10.2.2 Peripheral ties
No additions or amendments
9.10.2.3 Internal ties
No additions or amendments
9.10.2.4 Horizontal ties to columns and/or walls
No additions or amendments
9.10.2.5 Vertical ties
No additions or amendments
9.10.3 Continuity and anchorage of ties
No additions or amendments
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding Part 1: Design and construction
10 Additional rules for precast concrete elements and
structures
No additions or amendments
11 Lightweight aggregate concrete structures
No additions or amendments
12 Plain and lightly reinforced concrete structures
No additions or amendments
84
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 1: Design and construction
Annex RV K: Recommended system coefficients (informative)
RV K1 Values for reinforcements created by adhesive bonding:

Steel tabs
CFRP plates
sL0k
L1k
0.300   cc  f cm   ct  f ctm, surf
0.185 mm
0.366   cc  f cm   ct  f ctm, surf
0.201 mm
LFk
0
10.8   cc  f cm
0,89
Where:
fctm,surf
fcm
mean tensile strength of surface in N/mm² (according to Part 4)
mean cylinder compressive strength in N/mm² (according to Part 4)
cc
factor taking into account the long-term effects on compressive strength of
concrete.
cc in accordance with DIN EN 1992-1-1 in combination with the National Annex
ct
factor taking into account the long-term effects on axial tensile strength of concrete.
ct in accordance with DIN EN 1992-1-1 in combination with the National Annex
RV K2 System coefficient for columns:
Recommendations for pre-design:
[k0]
[k1]
[k2]
[k3]
[k4]
[k5]
[k6]
[k7]
[k8]
[k9]
= 0.2 · 1/(N/mm²)
= 2.0
= 0.25
= 0.7
= 1.0 (building)
= 1.0 (building)
= 0.75
= 0.39
= 0.89
= 0.44 · 10-2
85
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 1: Design and construction
Annex RV L Determination of cross-section values
(informative)
RV L1 Ultimate limit state
RV L1.1 General
(RV 1) In the area of linear-elastic concrete behaviour and pure bending stress (NEd = 0), the line of
zero strain is equivalent to the mechanical centroid of the cracked cross-section. For these conditions,
the special cases of rectangular cross-section and T-beam cross-section have been solved in the
following sections.
RV L1.2 Rectangular cross-sections
(RV 1) For rectangular cross-sections, the compression zone may be obtained by means of Equation
Error! Reference source not found.. Without compression reinforcement, s2 can be set to
zero.

x   L  L   S  S1  S2  



L  L  S  S1  S2 2  2  L  L  dL   S   S1  d  S2  d2     h

h

h
h  

(RV L.1)
Where:
S1 
AS1
bh
S2 
S 
ES
EC
L 
AS2
bh
L 
AL
bh
EL
EC
(RV 2) By way of simplification, the inner lever arms may be obtained by means of Equation
Reference source not found. or Error! Reference source not found.
Error!
zs = d  ka  x  d  0,4  x
(RV L.2)
zL = h  ka  x  h  0,4  x
(RV L.3)
RV L1.3 T-beams
(RV 1) For T-beams where the compression zone is located in the beam only, Equation
Reference source not found. where b = beff may be applied.
86
Error!
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 1: Design and construction
(RV 2) For T-beams where the compression zone is also located in the web, the compression zone
may be obtained by means of Equation Error! Reference source not found. and the
corresponding values in accordance with Equations Error! Reference source not found. and
Error! Reference source not found..
x    A  A2  B   h


A
ht
h
(RV L.4)
b

  ef f  1   S  S1  S2   L  L
b
 w

(RV L.5)
2


d
d
d 
h  b

(RV L.6)
B  2   t    ef f  1  2   L  L  L   S   S1   S2  2  
h
h
h 
 h   bw



(RV 3) By way of simplification, the inner lever arms may be obtained by means of Equation Error!
Reference source not found. orError! Reference source not found..
zs = d  ka  x  d  0,4  x
(RV L.7)
zL = h  ka  x  h  0,4  x
(RV L.8)
RV L2 In the ultimate limit state
(RV 1) Using the equilibrium of internal and external forces according to Equations Error!
Reference source not found. and Error! Reference source not found., the strains
and thus the forces and lever arms may be determined by iteration on the cracked cross-section. The
necessary equations are given below.
(RV 2) The equilibrium of internal and external forces is obtained when action-effect equals resistance.
(RV L.9)
M Rd = M Ed
(RV 3) The resistance of the cross-section to bending is calculated using reinforcement and its lever
arm according to Equation Error! Reference source not found..
(RV L.10)
M Rd = As1  Es   s1  (d  ka  x)  AL  EL  εL  (dL  ka  x)  As2  Es   s2  (ka  x  d 2 )
(RV 4) The equilibrium of inner forces is described by Equation Error! Reference source not found..
(RV L.11)
R  fcd  b  x  As2  Es   s2 = As1  Es   s1  AL  EL  L
(RV 5) The strains of the reinforcements may be obtained using concrete compression on the
assumption of even distribution of strains.
d  x fy d
 s2 =  c  2

(RV L.12)
x
Es
fy d
dx
 0 
x
Es
(RV L.13)
dL  x
  0   Lud
x
(RV L.14)
 s1 =  c 
L =  c 
(RV 6) The completeness coefficient and the factor for inner lever arm on the basis of the parabola
rectangle diagram for concrete are determined as a function of concrete compression obtained by
means of Equations Error! Reference source not found. and Error! Reference source not found..
Simplified determination of concrete compressive forces using a tension block in accordance with DIN
EN 1992-1-1 is permissible.

1 000


for  c  0.002
1 000 c   0.5  12   c 


R = 
2

1
for 0.002   c  0.0035

3 000   c
87
(RV L.15)
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 1: Design and construction
8  1 000   c

for  c  0.002

4  (6  1 000   c )
ka = 
1 000   c  (3 000   c  4)  2

for 0.002   c  0.0035
 2 000   c  (3 000   c  2)
(RV L.16)
RV L3 Approximation method for the ultimate limit state
(RV 1) By way of simplification, the reinforcing steel tension can be obtained from the prestrain by
means of Equation Error! Reference source not found. from the moment during
reinforcement to serviceability level.
 s,0 ( x) =
M Eqp,0 ( x)
zs  As
=
M Eqp,0 ( x)
0.85  d  As
 f yd
(RV L.17)
(RV 2) The effective moment after reinforcement may be obtained by means of Equation
Reference source not found..
ΔM Ed ( x ) = M Ed, V ( x )  M Eqp,0 ( x )
Error!
(RV L.18)
(RV 3) By way of simplification, the reinforcing steel tension in the reinforced state can be obtained by
means of Equation Error! Reference source not found..
 s ( x) =  s,0( x) 
Where
z m  0.75 
ΔM Ed ( x)
d  Es

 fy d
zm
dL  ELm  AL  d  ES  AS
d L  ELm  AL  d  ES  AS
ELm  AL  ES  AS
(RV L.19)
(RV L.20)
(RV 4) By way of simplification, the plate force as a function of reinforcing steel tension in the
reinforced state can be obtained by means of Equation Error! Reference source not found..
d L  ELm  AL
 ΔM Ed ( x)

 z
d L  ELm  AL  d  ES  AS
m
FLEd ( x) = 
M Ed,V ( x)

 As  f yd

zm
for  s ( x)  f yd
(RV L.21)
for  s ( x)  f yd
88
DEUTSCHER AUSSCHUSS FÜR
(GERMAN
COMMITTEE
FOR
CONCRETE)
STAHLBETON
REINFORCED
DafStb Guideline on
Available from Beuth Verlag GmbH, Berlin, sales number 650XX
on the reinforcement of concrete parts
with adhesive bonding
Part 2: Products and systems for reinforcement
Draft March 2012
The requirements of Directive 98/34/EC of the European Parliament and of the Council of 22 June
1998 laying down a procedure for the provision of information in the field of technical standards and
regulations and of rules on Information Society services (OJ L 204 of 21 July 1998, p. 37), recently
amended by Directive 2006/96/EC (OJ L 363 of 20 December 2006, p. 81) have been taken into
account.
Regarding the standards, other documents and technical specifications related to products or test
procedures named in this Guideline, the rule is that other products and test procedures may be
applied if they meet the standards and other provisions and/or technical specifications of other EU
Member States, Turkey or other EFTA State, that is a Contract State of the European Economic Area
(EEA), provided the specified level of protection with regard to safety, health and suitability of use is
equally permanently achieved.
Published by:
Deutscher Ausschuss für Stahlbeton e. V. – (DAfStb)
Budapester Straße 31
D – 10787 Berlin-Tiergarten
Phone: 030 2693-1320
info@dafstb.de
The Deutsche Ausschuss für Stahlbeton (DAfStb) retains all rights, including translation into foreign languages. This document or any
part thereof may not be photocopied or otherwise reproduced without the explicit permission of DAfStb.
Contents List Part 2
1 Scope of application ................................................................................................... 85
2 Normative references .................................................................................................. 85
3 Reinforcement system ................................................................................................ 85
3.1 General .....................................................................................................................85
3.2 Adhesive ..................................................................................................................85
3.3 CFRP plates .............................................................................................................86
3.4 CF sheeting ..............................................................................................................86
3.5 Products for levelling layers ...................................................................................87
3.6 Primer for corrosion protection ..............................................................................87
3.7 Steel sections and fastening systems ...................................................................87
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 2: Products and systems for reinforcement
1 Scope of application
(1) This part of the Guideline contains a general description of products and systems for reinforcement
of concrete parts with adhesive bonding.
(2) Application of this Guideline in areas subject to building inspectorate approval shall require a
general building inspectorate approval as usability verification of the reinforcement systems.
(3) The requirements for products and systems for reinforcement of concrete parts in accordance with
general building inspectorate approvals shall be satisfied.
2 Normative references
DIN 1045-2, Plain, reinforced and prestressed concrete structures – Part 2: Concrete – Specification,
properties, production and conformity – Application rules for DIN EN 206-1
DIN 18551, Shotcrete - National rules for series DIN EN 14487 and rules for design of shotcrete
constructions
DIN EN 206-1, Concrete - Part 1: Specification, performance, production and conformity
DIN EN 1993-1-1, Eurocode 3: Design of steel structures - Part 1-1: General rules and rules for
buildings
DIN EN 2561, Aerospace series - Carbon fibre reinforced plastics - Unidirectional laminates - Tensile
test parallel to the fibre direction
DIN EN 10025-2, Hot rolled products of structural steels - Part 2: Technical delivery conditions for nonalloy structural steels
DIN EN 14487-1, Sprayed concrete - Part 1: Definitions, specifications and conformity
3 Reinforcement system
3.1 General
(1) A reinforcement system consists of different construction products matched to each other. Proof of
their suitability as part of the reinforcement system shall be furnished within a general building
inspectorate approval of the reinforcement system (e.g. general building inspectorate approval or
permit in individual cases). The Guideline wording will generally use the term ‘general building
inspectorate approval’ for this purpose.
(2) The products of the reinforcement system shall bear a mark of conformity [German designation: ÜZeichen] from the manufacturer in accordance with the regulations on marks of conformity of the
respective states.
(3) A reinforcement system consists of:

Reinforcement elements made of carbon fibre materials (CFRP plates or CF sheeting) or flat
steel sections (steel tabs or angle steel);

the adhesive;

a primer on epoxy resin basis as part of the corrosion protection system for steel parts;

reprofiling mortar on an epoxy resin basis including screed.
3.2 Adhesive
(1) Only adhesives approved for the application shall be used in the adhesive bonding of
reinforcement sections. The requirements of adhesives are regulated in the general building
inspectorate approvals.
(2) The following information shall be available on the adhesive:

product designation and manufacturer;

batch number;

date of minimum durability;

minimum and maximum application temperatures:

mixture ratio of epoxy resin and curing agent;
91
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 2: Products and systems for reinforcement

reference to occupational regulations (Code) and hygiene;

information on storage;

mixing instructions;

pot life within the application temperature;

danger warnings;

disposal instructions.
(3) The Guideline shall only be applied if the characteristic tensile strength of an adhesive on epoxy
resin basis for the surface bonding of reinforcement sections ≥ 14 N/mm 2 is verified within in-house
production control in accordance with general building inspectorate approvals.
NOTE: Establishing a minimum value for the characteristic tensile strength will ensure that the basic
assumption of design, namely that the concrete layer close to the surface will fail, has been satisfied.
(4) For plates bonded in indent cuts, the respective characteristic values for compressive and tensile
strength can be found in the general building inspectorate approvals.
3.3 CFRP plates
(1) The carbon fibre reinforced plates (CFRP plates) shall be factory-manufactured sections made of
epoxy resin containing a specific amount of unidirectional carbon fibres as defined in product
approvals. The plates are characterised by

their mechanical properties in the direction of the fibres (tensile strength, modulus of elasticity,
ultimate strain);

the characterisation of the matrix resin (binding agent type, glass transition temperature)

their geometric dimensions (plate thickness and width);

their surface design (smooth, polished, profiled).
(2) Corresponding definitions are included in the respective general building inspectorate approvals or
the manufacturer’s instructions.
(3) The design equations in Part 1 of this Guideline apply to CFRP plates with a thickness between 1
mm and 3 mm.
(4) The mean modulus of elasticity of the CFRP plates determined in accordance with DIN EN 2561
must be in a range of 150 to 230 kN/mm² if this Guideline is applied.
3.4 CF sheeting
(1) The carbon fibre sheets (CF sheeting) are unidirectionally aligned carbon fibres. The sheeting is
characterised by the following properties:

tensile strength in the direction of fibres;

modulus of elasticity in the direction of fibres;

ultimate strain in the direction of fibres;

geometric dimensions and weight per area

calculated thickness (equals theoretical thickness)
(2) Corresponding definitions are included in the respective general building inspectorate approvals or
the manufacturer’s instructions.
(3) When using confinement in the reinforcement columns, the following additional system coefficients
shall be substituted with the system-specific factors from the general building inspectorate approvals:
[k0]
[k1]
[k2]
[k3]
factor for determining the minimum thickness of the confining reinforcement to ensure the
strictly monotonous increase in the stress-strain relations of confined concrete, which
underlies the design concept.
factor for determining characteristic compressive strength of confined concrete
factor taking into account the effect of component edge conditions on the presumable limit
strain of CF sheeting
factor taking into account the effect of temperature on the presumable limit strain of CF
sheeting
92
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 2: Products and systems for reinforcement
[k4]
[k5]
[k6]
[k7]
[k8], [k9]
factor taking into account the effect of moisture on the presumable limit strain of CF
sheeting
factor taking into account the effect of action type (predominantly static or non-static) on
the presumable limit strain of CF sheeting
factor taking into account the effect of duration of actions on the applicable limit strain of
CF sheeting
factor for determining the effective creep of confined concrete
factors for determining the loadbearing component of the confined column that will not
result in damage in the serviceability limit state
3.5 Products for levelling layers
To re-establish the profile of defective spots in the substrate to which the plate is bonded or imbedded
in, the following products with verified properties may be used:

Repair concrete or mortar of strength class M3 in accordance with the Repair Guideline, Part 2:
construction products and application, Section 4.2;

Concrete in accordance with DIN EN 206-1/DIN 1045-2 taking into account the respective
exposure class;

Cement-bound concrete and grouting mortar in accordance with DAfStb Guideline “Production
and use of cement-bound grouting concrete and grouting mortar”, taking into account the
respective exposure class;

Sprayed concrete in accordance with DIN EN 14487-1 in combination with DIN 18551 taking into
account the respective exposure class;

Repair mortar in accordance with general building inspectorate approvals may be used to repair
the profile of small-area surface irregularities.
3.6 Primer for corrosion protection
(1) Primer approved for the application shall be used in the corrosion protection of steel section. The
requirements of primers are regulated in the general building inspectorate approvals.
(2) The Guideline shall only be applied if the characteristic tensile strength of the primer for steel
sections ≥ 14 N/mm2 is verified within in-house production control in accordance with general building
inspectorate approvals.
(3) The following information shall be available on the primer:

product designation and manufacturer;

batch number;

date of minimum durability;

minimum and maximum application temperatures:

mixture ratio of epoxy resin and curing agent;

reference to occupational regulations (Code) and hygiene;

information on storage;

mixing instructions;

information on curing period until characteristic tensile strength is reached;

pot life within the application temperature;

danger warnings;

disposal instructions.
3.7 Steel sections and fastening systems
(1) Steel sections shall be made of S235 steel, quality class JR or J2 in accordance with
DIN EN 10025-2. The characteristic material data for S235 steel in accordance with DIN EN 10025-2
can be found in DIN EN 1993-1-1, Table 3.1.
(2) S355 steel in accordance with DIN EN 10025-2 may also be used. For the design, no material
characteristics higher than those in DIN EN 1993-1-1, Table 3.1 may be used for S235 steel.
93
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 2: Products and systems for reinforcement
(3) Grade JR steel in accordance with DIN EN 10025-2, analogous to use of J2 steel with a steel tab
thickness tL ≤ 15 mm may be used under the following conditions:

use in components subject to predominantly static actions

the nominal yield strain in the panel in the ultimate limit state will be limited to 80 %.
(4) If steel parts are to be anchored on the component, fastening systems approved for the application
in general building inspectorate approvals shall be used. The anchor screws shall comply with
strength class 4.6, 5.6, 8.8 or 10.9.
94
DEUTSCHER AUSSCHUSS FÜR
(GERMAN
COMMITTEE
FOR
CONCRETE)
STAHLBETON
REINFORCED
DafStb Guideline on
Available from Beuth Verlag GmbH, Berlin, sales number 650XX
on the reinforcement of concrete parts
with adhesive bonding
Part 3: Construction
Draft March 2012
The requirements of Directive 98/34/EC of the European Parliament and of the Council of 22 June
1998 laying down a procedure for the provision of information in the field of technical standards and
regulations and of rules on Information Society services (OJ L 204 of 21 July 1998, p. 37), recently
amended by Directive 2006/96/EC (OJ L 363 of 20 December 2006, p. 81) have been taken into
account.
Regarding the standards, other documents and technical specifications related to products or test
procedures named in this Guideline, the rule is that other products and test procedures may be
applied if they meet the standards and other provisions and/or technical specifications of other EU
Member States, Turkey or other EFTA State, that is a Contract State of the European Economic Area
(EEA), provided the specified level of protection with regard to safety, health and suitability of use is
equally permanently achieved.
Published by:
Deutscher Ausschuss für Stahlbeton e. V. (DAfStb)
Budapester Straße 31
D – 10787 Berlin-Tiergarten
Phone: 030 2693-1320
info@dafstb.de
The Deutsche Ausschuss für Stahlbeton (DAfStb) retains all rights, including translation into foreign languages. This document or any
part thereof may not be photocopied or otherwise reproduced without the explicit permission of DAfStb.
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
Contents List Part 3
1 Scope of application .................................................................................................... 93
2 Normative references .................................................................................................. 93
3 Requirements for the contractor................................................................................ 93
3.1 General .................................................................................................................... 93
3.2 Staff .......................................................................................................................... 94
3.2.1
3.2.2
Project supervisor ........................................................................................................... 94
Skilled site personnel ...................................................................................................... 94
3.3 Equipment ............................................................................................................... 95
3.4 Subcontractor.......................................................................................................... 95
4 Execution of the component reinforcements .......................................................... 95
4.1 General .................................................................................................................... 95
4.2 Requirements on the reinforcement system ......................................................... 96
4.3 Climate and ambient conditions ............................................................................ 96
4.4 Substrate priming ................................................................................................... 96
4.4.1
4.4.2
4.4.3
Bonding of CFRP plates or steel tabs to component surface using adhesive ............... 96
Bonding of CF sheeting .................................................................................................. 97
Bonding in indent cuts in the concrete edge zone ......................................................... 97
4.5 Reprofiling work ...................................................................................................... 98
4.6 Priming of fibre composite materials and steel tabs for adhesive bonding ....... 98
4.6.1
4.6.2
4.6.3
CFRP plates ................................................................................................................... 98
Steel tabs ........................................................................................................................ 98
CF sheeting .................................................................................................................... 99
4.7 Mixing the adhesive ................................................................................................ 99
4.8 Adhesive work ......................................................................................................... 99
4.8.1
4.8.2
4.8.3
4.8.4
General determinations .................................................................................................. 99
Bonding of CFRP plates or steel tabs to component surface using adhesive ............... 99
Bonding of CF sheeting to component surface using adhesive ................................... 100
CFRP plates bonded in indent cuts .............................................................................. 100
4.9 Actions on the structure ....................................................................................... 100
4.10 Component exposures during execution ............................................................ 100
4.11 Limit deviations ..................................................................................................... 100
5 Supervision of the execution (contractor’s internal control) ...............................100
5.1 General requirements ........................................................................................... 100
5.2 Supervision of substrate priming ........................................................................ 101
5.2.1
5.2.2
5.2.3
Check of concrete compressive strength ..................................................................... 101
Check of the surface tensile strength of the substrate ................................................. 102
Check of the concrete cover prior to cutting work performed for reinforcement bonded in indent
cuts ............................................................................................................................... 102
5.3 Check of the reprofiling work ............................................................................... 104
5.3.1
5.3.2
Check of bond strength between reprofiled layer and substrate .................................. 104
Check of the compressive strength of the reprofiling material ..................................... 104
5.4 Supervision of the adhesive work........................................................................ 105
5.4.1
5.4.2
Curing test of the adhesive on the component, with levelling layer, if necessary ........ 105
Mechanical properties of the adhesive and primer ...................................................... 105
90
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
5.4.3
Adhesive bond on pretreated steel ............................................................................... 106
5.5 Checks after execution ......................................................................................... 106
5.6 Corrosion protection work ................................................................................... 107
Annex A Permanent inspection body (normative)..................................................108
Annex B Test methods during execution (normative) ...........................................109
Annex C Supervision of work by an accredited inspection body (normative) ...110
Annex D Certificate of suitability for contractors for reinforcement of concrete
components using adhesive bonding (normative) ...............................................111
D.1 General .................................................................................................................. 111
D.2 Formal requirements for the operation and the skilled personnel .................... 111
D.3 Suitability tests...................................................................................................... 112
D.4 Certification of the contractor .............................................................................. 114
1 Scope of application ..................................................................................................117
2 Normative references ................................................................................................117
3 Requirements of the component to be reinforced ................................................117
3.1 Special regulations for steel tabs, CFRP plates and CF sheeting bonded to a surface
............................................................................................................................. 117
3.2 Special rules for CFRP plates bonded in indent cuts ......................................... 117
4 Principles.....................................................................................................................118
4.1 General .................................................................................................................. 118
Annex A Determination of the expected mean value .............................................119
91
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
Foreword
(1) The requirements and data in the product and system approvals shall be observed.
(2) The usage conditions for the application of the system are included in the approvals.
92
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
1 Scope of application
This part of the Guideline establishes rules for the execution of reinforcement measures for parts using
adhesive bonding.
2 Normative references
DIN 1045-2, Plain, reinforced and prestressed concrete structures – Part 2: Concrete – Specification,
properties, production and conformity – Application rules for DIN EN 206-1
DIN 1045-3, Plain, reinforced and prestressed concrete structures – Part 3: Execution of structures
DIN 18551, Shotcrete - National rules for series DIN EN 14487 and rules for design of shotcrete
constructions
DIN 18800-7, Steel structures - Part 7: Execution and manufacturer qualification
DIN V 18028, Injection products according to DIN EN 1504-5:2005-03 with special features
DIN EN 196-1, Methods of testing cement - Part 1: Determination of strength
DIN EN 206-1, Concrete - Part 1: Specification, performance, production and conformity
DIN EN 1504-5, Products and systems for the protection and repair of concrete structures - Definitions,
requirements, quality control and evaluation of conformity - Part 5: Concrete injection
DIN EN 1542, Products and systems for the protection and repair of concrete structures - Test methods Measurement of bond strength by pull-off
DIN EN 1766, Products and systems for the protection and repair of concrete structures - Test methods Reference concretes for testing
DIN EN 1990, Eurocode: Basis of structural design
DIN EN 1992 1-1, Eurocode 2: Design of concrete structures - Part 1-1: General – Common rules for
building and civil engineering structures
DIN EN 10025-2, Hot rolled products of structural steels - Part 1: Technical delivery conditions
DIN EN 13670, Execution of concrete structures
DIN EN 13791, Assessment of in-situ compressive strength in structures and precast concrete components
DIN EN 14487, Sprayed concrete - Part 1: Definitions, specifications and conformity
DIN EN ISO 12944-2, Paints and varnishes - Corrosion protection of steel structures by protective paint
systems - Part 2: Classification of environments
DIN EN ISO 12944-4, Paints and varnishes - Corrosion protection of steel structures by protective paint
systems - Part 4: Types of surface and surface preparation
DIN EN ISO 12944-7, Paints and varnishes - Corrosion protection of steel structures by protective paint
systems - Part 7: Execution and supervision of paint work
RiLi SIB, DAfStb Guideline ‘Protection and repair of concrete components’ (‘Schutz und Instandsetzung von
Betonbauteilen’), October 2001 edition
3 Requirements for the contractor
3.1 General
(1) Requirements with regard to staff, equipment and documentation are imposed on the contractor
regarding the execution and supervision of reinforcement using adhesive bonding.
(2) Evidence of qualification of the contractor shall be issued by an inspection body certified by the German
Institute of Structural Engineering (Deutsches Institut für Bautechnik (DIBt))

through certification in accordance with the manufacturer and user regulation (HAVO) on the repair of
loadbearing components the stability of which is in danger

a suitability certificate for reinforcement of concrete components reinforced by adhesive bonding
(requirements in accordance with Annex D).
(3) Only products approved and tested in the system may be used for reinforcement measures using
adhesive bonding.
-
(4) The manufacturer’s information on the execution according to the rules of general building
inspectorate approvals for reinforcement systems shall be complied with.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
3.2 Staff
3.2.1 Project supervisor
(1) The tasks and responsibilities of the project supervisor are regulated in the respective Regional Building
Regulations. If the project supervisor does not possess the required technical knowledge in accordance with
the provisions of the section, a competent and experienced technical project supervisor shall be consulted.
(2) The tasks of the project supervisor as the qualified project manager for reinforcement measures using
adhesive bonding are in particular:

checking materials and components used for conformity with the information in the construction
documentation and examination of performance specifications in the meaning of this Guideline;

planning work flows based on the planning documentation for the reinforcement measures created by a
competent planner;

use of intended material with the required certificates of conformity;

initiating the required tests, if necessary in consultation with an inspection body in accordance with
Annex A;

reporting of the repair measure to the inspection body;

evaluation of technical qualification of construction site personnel used for the measure;

analysis of results of internal control at the contractor and drawing of conclusions from the results for
further proceedings;

submission of the results of internal control to the inspection body.
(3) The manager responsible shall be certified as a qualified manager in the suitability verification of the
contractor in accordance with Annex D.
3.2.2 Skilled site personnel
(1) There shall always be a skilled contractor’s employee who is especially trained in construction work
present on each construction site at all times, who possesses knowledge, skills and practical experience in
concrete and other construction material technology, as well as in the use of the designated products. Proof
of the capability to work in accordance with this Guideline shall be furnished to the recognised inspection
body in the form of the following two certificates:

certificate issued by the training committee for “using plastics in concrete construction” [“Verarbeiten
von Kunststoffen im Betonbau”] from Deutscher Beton und Bautechnik-Verein E. V. in the form of the
SIVV-Schein (protection, repair, joining and reinforcement of components). Provisions regarding regular
continuing education shall be observed.

Suitability verification of the skilled personnel for reinforcement of parts using adhesive bonding in
accordance with Annex D.
(2) Tasks of skilled personnel include the practical execution of the reinforcement measure according

to specifications in the planning and execution documentation, such as work plan, execution
instructions;

instruction and supervision of other construction site personnel and/or subcontractor(s) responsible for
executing the reinforcement measure;

conducting of tests required for internal control and recording of the results.
(3) The contractor’s skilled personnel responsible for working according to this Guideline shall be certified as
skilled personnel with special knowledge and experience in:

the repair of loadbearing components in accordance with RiLi SIB. This evidence may be furnished in
the form of a certificate for “using plastics in concrete construction” [“Verarbeiten von Kunststoffen im
Betonbau” (SIVV-Schein)] from Deutscher Beton und Bautechnik-Verein E. V. and

-
reinforcement of parts using adhesive bonding according to the provisions in Annex D.
(4) The contractor shall furnish evidence that the skilled personnel responsible will receive training
and education in protection and reinforcement measures at intervals of no more than three years,
enabling them to carry out all measures necessary for proper execution of a reinforcement measure
including internal control.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
3.3
Equipment
(1) For the execution of reinforcement work using adhesive bonding, the implements and equipment that
allow proper priming of substrate, skilled carrying out of work, determination of required properties of
materials and checking work results shall be at the site in a functional state and at the required time. In
particular, these are equipment and implements for

storage of construction materials;

preparation of the substrate;

measuring and mixing products;

processing and after-treatment of processed products;

performance of proper internal control.
(3) All equipment and implements shall be checked for proper function prior to their initial use and
then at regular intervals thereafter.
Table 3.1 Recommended equipment for operations (informative)
1
2
3
4
5
6
7
8
Recommended implements
Hygrometer
Thermometer for air and component temperatures
Crack width meter (template), magnifying glass for measurement purposes
Instruments for measuring material or component moisture, e.g. CM meter (see Annex B)
Adhesive pull strength tester including test pieces 20 mm and 50 mm and a Sa3 blasted steel plate
with a thickness of  15 mm
Sample specimen forms 40 mm x 40 mm x 160 mm in accordance with DIN EN 196-1 and accessories
Storage facilities for test specimens or climate chamber
Scales with a 20 capacity and a minimum readout accuracy of 1 g.
NOTE: The weighing of individual components on the site in exceptional cases only.
9 Core drilling machine and accessories (also suited for overhead use, if applicable)
Equipment for substrate priming, e.g. by chiselling, blasting, milling, grinding and for cleaning, as well
10
as tools for cutting indents
11 Suitable mixing equipment for different products
12 Implements for conveying, applying, smoothing, spreading
13 Stud finder
14 Flatness measuring device
3.4 Subcontractor
(1) If the contractor hires subcontractors for subprojects, the contractor shall make sure that the
subcontractor satisfies the requirements in accordance with Sections Error! Reference source
found. through Error! Reference source not found..
not
(2) Only skilled personnel with a suitability certificate on the reinforcement of concrete components in
accordance with Annex D of a contractor certified in accordance with Section Error! Reference source
not found. may carry out the adhesive bonding work.
4 Execution of the component reinforcements
4.1 General
(1) As part of the execution, a comparison of values obtained from internal control of execution in
accordance with Section Error! Reference source not found. with the random sample values obtained in
the planning phase shall be used to check whether they are representative for the actual state of the
component (plausibility check). In the event of deviation, these shall be reported to the customer, so that the
competent planner may review the planning documents and revise them, if needed.
(2) Prior to the reinforcement measure, the contractor or subcontractor shall develop a standard operating
procedure with information on the execution.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
4.2 Requirements on the reinforcement system
(1) The requirements on the reinforcement system (fibre composite materials, steel tabs, adhesive, corrosion
protection, levelling mortar) are specified in the general building inspectorate approvals, in particular:

mechanical properties;

application and processing temperatures;

moisture conditions;

roll diameter of the fibre composite material or bending diameter of the steel tabs;

if applicable, protective layers for certain exposures of the reinforced component area.
(2) For each reinforcement system, the manufacturer or system supplier of the products shall provide
“information on execution” (formerly: execution instructions). They shall contain all the information
necessary for execution in the meaning of usability verification. Execution data for certain materials may
contain additional requirements on the concrete substrate, the climate conditions and/or provisions on the
limitation of vibrations.
4.3 Climate and ambient conditions
(1) During application and for an appropriate period thereafter, the temperatures of the concrete substrate
and the air layer immediately above it shall be at least 8 °C and the maximum component moisture 4 %.
When using plastic-bound materials, the surface temperature of the concrete or the respective substrate
shall always be at least 3 K above the dew point. The air humidity must not exceed 75 %. If applicable,
deviating values shall be specified in the general building inspectorate approvals.
(2) With regard to limit values, the temperature development over the period of execution and for an
appropriate period thereafter as well as cooling off overnight shall be taken into account (based on weather
forecasts, taking into consideration regional conditions).
(3) If vibrations (e.g. from construction work or traffic) are expected during curing of the potential levelling
layer, these shall be mitigated or eliminated as necessary to avoid damage to the adhesive bond.
4.4 Substrate priming
4.4.1 Bonding of CFRP plates or steel tabs to component surface using adhesive
(1) For reinforcement measures on concrete component using adhesive bonding to be successful with
regard to type, quality and duration, the respective concrete surface must have certain properties. This will
require substrate priming.
(2) The concrete surface shall be primed for the adhesive until the grain particles with a diameter > 4 mm
become visible; this can be achieved for example for example by

blasting with solid blasting materials,

shot blasting,

treatment with a blasting gun,

grinding.
(3) Cracks in the concrete in the reinforcement zone that might result in corrosion in the reinforcement or
cracks with liquid penetration shall be treated in accordance with RiLi SIB.
(4) The concrete surface to be bonded shall be free from dust and loose particles. Furthermore the concrete
surface shall be dry in the meaning of RiLi SIB. The moisture content of the component shall not exceed 4 %
(see Error! Reference source not found. (1)). There must be no cracks or material detachments
parallel to the surface or shell-shaped near the surface, or any foreign particles such as rubber debris,
removal agents, unsuitable old coatings, efflorescence, oil, growth etc. that could impair the adhesive bond.
(5) After substrate priming, the surface tensile strength of the concrete substrate shall be checked in
accordance with DIN EN 1542. The expected mean surface tensile strength of the concrete or the reprofiled
concrete surface in the zone of the adhesive bonding shall be evaluated in accordance with Part 4 of this
Guideline. The expected mean surface tensile strength shall be at least 1.0 N/mm 2. If a higher value is used
in the static calculation of the adhesive bond, an analysis shall be conducted for it. If the required surface
tensile strength cannot be attained, the competent planner shall be notified prior to performing the adhesive
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
work. Additional tests may be necessary. Lower values may be an indication of insufficient component
stability.
(6) The surface of the concrete to be bonded by adhesive should be as large as possible (see (8)). If
necessary, a levelling layer in accordance with section Error! Reference source not found. shall be
installed.
(7) Unevenness up to 4 mm may be levelled by the adhesive.
(8) Unevenness in the range between 4 and 30 mm shall be levelled by grinding or reprofiled using a
levelling layer in accordance with Section Error! Reference source not found.. Unevenness > 30
mm shall be evaluated by the structural engineer. Exempt from this are spot defects in the concrete, such as
reprofiled concrete chips or pits. These shall be exposed properly and reprofiled.
4.4.2
Bonding of CF sheeting
(1) The provisions in Error! Reference source not found.. shall apply to the adhesive bonding of CF
sheeting. Cement-bound concrete substitutes or concrete as a substrate shall be primed by grinding prior to
bonding.
(2) Suitable methods for substrate priming are grinding, blasting or jet blasting. Cement slurry shall be
removed until the grain structure becomes visible. Unevenness or indentations of 3 mm or more shall be
reprofiled using a suitable epoxy resin mortar in accordance with general building inspectorate approvals.
Over a test section of 300 mm, the variation from flatness must not exceed 1 mm. The corners of column
confinements shall be curved at a radius of r ≥ 25 mm. At the time of adhesive bonding, the surfaces shall be
dry (residual moisture < 4 %) and free from dust and particles. The adhesion strength values shall be
adjusted to the values assumed in the static calculation.
4.4.3 Bonding in indent cuts in the concrete edge zone
(1) The CFRP plates shall be bonded perpendicular to the concrete edge zone. For this purpose, indents
perpendicular to the component need to be cut into the component surface.
(2) The concrete cover of the existing reinforcing steel reinforcement shall be so that the reinforcement will
not be damaged by the cutting work. An analysis of the concrete cover in the area of the plates to be bonded
in indent cuts shall be conducted and the results documented.
(3) The following parameters shall be observed:

The depths of the cut in the concrete shall be designed so that the plate can be fully embedded in the
cut, taking into account the levelling of irregularities. The maximum permissible cut depth ts is obtained
as follows:
ts ≤ c – Δcdev
Where
c: existing concrete cover of reinforcement in mm
cdev: allowance in design for deviation in mm
cdev = cdevice + ccut + ccomponent
Where:
cdevice
device-specific defect limit, [DBV-Merkblatt ‘Betondeckung’] or manufacturer’s information,
minimum 1 mm
ccut
allowance in design for deviation, minimum 2 mm
ccomponent for slabs, ccomponent = 0 mm is permissible, for all other components, the assumption is
ccomponent minimum 2 mm.
ccomponent may be omitted if the accuracy of the concrete cover measurement can be increased by
suitable measures, e.g. random sampling of concrete cover through spot exposure of the
reinforcement.

The width of the indent cut bs shall satisfy the following condition:
tL + 1 mm ≤ bs ≤ tL + 3 mm
Where
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
tS depth of the cut in mm (see above)
tLplate thickness in mm
(4) The indent cuts shall be free from dust and particles. Non-loadbearing layers on the side surfaces of the
cut shall be removed. The maximum moisture content in the indent cut zone shall not exceed the values in
the product approval.
4.5 Reprofiling work
(1) Reprofiling work on the substrate may be necessary if

there are defect spots in the existing concrete, such as concrete chipping and pits;

unevenness in the component surface does not allow even adhesive bonding of the reinforcement to
satisfy the requirements in accordance with Section Error! Reference source not found.;

even after substrate priming, irregular or defective spots over 4 mm remain;

the concrete cover is insufficient.
(2) Uneven or defective spots in the substrate of less than 4 mm may be levelled with an adhesive in
accordance with Section Error! Reference source not found.. Unevenness or defective spots in the
substrate greater than 4 mm shall be levelled by grinding or reprofiling.
(3) Reprofiling serves the purpose of static loadbearing capacity. To level out small- or large-area
unevenness in the concrete surface or defects in the adhesive area, only the following materials may be
used, provided the necessary bond strength of the concrete substrate is reached and an analysis for largearea reprofiling is provided in accordance with Section Error! Reference source not found.:

Repair concrete or mortar of strength class M3 in accordance with RiLi SIB, Part 2: construction
products and application, Section 4.2;

Concrete in accordance with DIN EN 206-1/DIN 1045-2 taking into account the respective exposure
class;

Cement-bound concrete and grouting mortar in accordance with DAfStb Guideline “Production and use
of cement-bound grouting concrete and grouting mortar”, taking into account the respective exposure
class;

Sprayed concrete in accordance with DIN EN 14487 in combination with DIN 18551 taking into account
the respective exposure class.

Repair mortar in accordance with general building inspectorate approvals may be used to repair the
profile of small-area unevenness.
(4) RiLi SIB shall apply for the performance of reprofiling work.
(5) For large-area levelling layers, the roughness of the substrate specified by the competent planner shall
be prepared.
4.6 Priming of fibre composite materials and steel tabs for adhesive
bonding
4.6.1 CFRP plates
(1) The CFRP plates must not be pressed off or subjected to sharp transverse pressing. If applicable, they
only may be cut perpendicular to the direction of fibre on the construction site.
(2) Prior to bonding, the plate surface shall be primed in accordance with the general building inspectorate
approval.
NOTE When using solvents, the occupational health protection provisions of the German Employer’s Liability Insurance
Association shall apply.
4.6.2 Steel tabs
(1) The material of the steel parts to be bonded and the anchor bolts for mounting them can be found in the
general building inspectorate approval.
(2) Welding work on steel parts to be joined shall only be performed by companies that possess proof of
manufacturer qualification in accordance with DIN 18800-7, Class B. Welding work on bonded steel parts is
not permissible.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
(3) Prior to bonding, steel parts shall be blasted with solid particles until they reach a purity level of Sa 2½ in
accordance with DIN EN ISO 12944-4.
(4) Steel parts for external use shall be coated twice on both sides with a minimum layer thickness of 120 µm
of a primer approved according to general building inspectorate approvals. Upon curing of the primer, it shall
be ground on the surfaces to be bonded. However, it must not be ground for exterior use. Prior to bonding,
the ground surfaces shall be dusted and cleaned using a solvent in accordance with manufacturer’s
specifications.
(5) For internal use (XC1), a procedure in accordance with Section (4) is permissible. Full coating with a
primer may be foregone in internal use (XC1) if the steel parts are bonded immediately upon blasting or if the
steel parts are protected from corrosion by sealing in PE foil until bonding.
(6) After bonding of the steel tabs, the non-bonded steel surfaces shall receive additional corrosion
protection of C3 or higher in accordance with DIN EN ISO 12944-2. This corrosion protection shall be
applied to the component surface over and up to 10 mm of the adhesive thickness to the left and right of the
steel tab.
NOTE When using solvents, the occupational health protection provisions of the German Employer’s Liability
Insurance Association shall apply.
4.6.3 CF sheeting
(1) The CFRP sheeting must not be rounded off or subjected to sharp transverse pressing.
(2) The sheeting surface shall be free from dust prior to adhesive bonding.
(3) Additional information of the respective general building inspectorate approvals shall be taken into
account.
4.7 Mixing the adhesive
(1) The temperature range recommended by the manufacturer for mixing the adhesive shall be complied
with. If the adhesive temperature is below that, additional mixing might be necessary.
(2) Mixing of the adhesive components shall be done mechanically using a slow-speed (< 300 rpm) mixer.
The components shall be mixed until a homogenous and ream-free adhesive mass is obtained. The mixture
must be moved to a different container. The finished mixture must not contain lumps or similar; its colour
shall be even.
(3) No significant air volumes shall be mixed in.
4.8 Adhesive work
4.8.1 General determinations
(1) During the adhesive work, the minimum temperatures of air and concrete and the maximum values of
relative air humidity according to general building inspectorate approvals must be observed. The
temperature of the component shall be 3 K higher than the dew point temperature of the air.
(2) The substrate of the concrete in the adhesive bonding zone shall be dry in the meaning of RiLi SIB. If in
doubt, a quantitative determination of the moisture content shall be conducted. The permissible moisture
content can be found in the general building inspectorate approvals.
4.8.2 Bonding of CFRP plates or steel tabs to component surface using adhesive
(1) Prior to bonding of the tabs or plates, a coat of adhesive shall be applied to the substrate with a notched
trowel to completely fill all valleys and small defects with the adhesive. If the surface has been ground, coat
application with a trowel may be foregone. The grain structure shall be visible in the ground surfaces and the
adhesive pull strength tests in accordance with Section Error! Reference source not found. shall
be conducted on the ground surfaces.
(2) The adhesive shall be applied to the tab or plate in the shape of a roof; that is, an equal angle profile with
a camber. Within the open time, the tabs or plates shall be pressed carefully and evenly into the scraped,
fresh adhesive layer. The adhesive is pushed out of the joint evenly forming a little bulge, to form a cured
adhesive layer with a total thickness of 1 mm to 5 mm maximum.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
(3) The adhesive shall be applied to the components and the components secured in their final position
within the open time according to the respective product specifications. After securing until the adhesive or
the reprofiling layer underneath have cured, the components must not be subjected to vibration or movement
that could damage the bond.
(4) For reinforcement using steel tabs, a support for the adhesive curing period will be required in
accordance with the provisions of the general building inspectorate approvals. The support period may be
shorter if adhesive pull tests according to Section Error! Reference source not found. show that
concrete failure has been achieved.
(5) CFRP plates may be bonded without further support.
(6) CFRP plates may be bonded in two layers only if specified in the static analysis. In this case, after curing
of the first bonded plate, its smooth and imprinted secondary bonding side shall be carefully roughened and
cleaned and degreased using a solvent in accordance with the manufacturer’s instructions. Any packaging
fabric on this side shall be removed. Further priming will not be necessary in this case. The second plate
layer shall be primed and bonded as described.
(7) In areas where the risk of mechanical damage after installation cannot be precluded, the plates shall be
protected against mechanical damage.
4.8.3 Bonding of CF sheeting to component surface using adhesive
(1) Depending on the system approval, a primer shall be applied prior to application of laminating resin.
Waiting times are in accordance with the respective general building inspectorate approvals. Depending on
the CF sheeting type, protective foils shall be removed and the sheeting worked into the fresh laminating
resin using a suitable tool such as a roller or rubber lip. Care should be taken that no folds or hollow pockets
form. The applied CF sheeting shall then be embedded in a layer of laminating resin. If several layers are
required, the above steps shall be repeated. The maximum and minimum temperature and humidity values
and application amounts can be found in the respective general building inspectorate approvals.
(2) In areas where the risk of mechanical damage after installation cannot be precluded, the sheeting shall
be protected against mechanical damage.
4.8.4 CFRP plates bonded in indent cuts
(1) The adhesive shall be applied to the cut to completely fill it. Within the open time, the plate shall then be
carefully pressed into the middle of the indent cut. It must be completely embedded by the indent cut.
(2) The bonded plate will not require securing while curing. In areas where the risk of mechanical damage
after installation cannot be precluded, the plates shall be protected against mechanical damage.
(3) Only products approved and tested in the system may be used for reinforcement using adhesive bonding.
4.9 Actions on the structure
(1) At component surface temperatures or mean air temperatures near the surface of 20 °C, actions on the
structure are usually permissible 2 days after completion of the adhesive work.
(2) At lower temperatures, the curing time may be longer, and at higher temperatures, the waiting time may
be shorter. The curing analysis on the component in accordance with Section Error! Reference source
not found.will determine the length of time.
(3) Actions on the reinforced structure are permissible after the levelling layer possesses sufficient strength.
This will be the case when the characteristic strength of the product is higher than the compressive strength
of the existing concrete and the bond strength with the substrate is greater than the nominal static bond
strength. This may have to be demonstrated in accordance with Section Error! Reference source not
found..
4.10 Component exposures during execution
During execution of reinforcement measures using adhesive bonding, the reinforced component areas shall
be protected from direct exposure to weather and mechanical loads.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
4.11 Limit deviations
The limit deviations in accordance with DIN EN 13670 or DIN 1045-3 shall apply. The limit deviations of
component dimensions shall apply with regard to effective static depth.
5 Supervision of the execution (contractor’s internal control)
5.1 General requirements
(1) The contractor shall ensure that

the CFRP plates, CF sheeting, adhesive, primer and products used for levelling layers bear the mark of
conformity;

the steel plates in accordance with DIN EN 10025-2 bear the CE-mark;

the expiry date (manufacturing date plus storage period) has not expired;

the specifications with regard to substrate priming, reprofiling and adhesive work as well as corrosion
and other protection measures have been satisfied.
(2) A standard operating procedure with information on the execution shall be created prior to the
reinforcement measure.
(2) Throughout the execution, the project supervisor, his substitute or the skilled site personnel shall keep
continuous, transparent records on data relevant to quality and durability. They shall contain at least the
following information:

Name, location and type of construction project;

Names of the executing and supervising skilled site personnel;

Designation of the reinforced component (beam, T-beam, field and/or column zone)

Number and dimensions of the plates, sheets or steel tabs;

Start and end of adhesive work;

Climate conditions, air temperature, humidity, dew point;

Component temperatures to reach curing of the adhesive and substrate moisture;

Analysis of the materials used, including supplier plant, batch number and installation location of each
batch;

Function analysis of implements used;

Results of tests conducted in accordance with Section Error! Reference source not found. through
Error! Reference source not found. with allocation to individual components or construction zones;

Verification of execution according to available planning documentation and standard operating
procedures; Documentation of deviations, if applicable.
(3) The documentation shall be available on the construction site. Upon request, the documentation as well
as delivery notes shall be made available to the representative of the inspection body or the competent
planner. Upon completion of the work, relevant documentation shall be submitted to the customer for
creating a construction log.
(4) Upon completion of the work, the results of major tests conducted within execution and supervision by
the contractor shall be made available to the inspection body for review upon request.
(5) Type, scope and frequency of supervision of execution by the contractor are specified in Sections Error!
Reference source not found. to Error! Reference source not found., unless otherwise
stipulated in standards DIN 1045, DIN 18551, RiLi SIB or DAfStb Guideline “Production and use of cementbound grouting concrete and grouting mortar”.
(6) Type, scope and frequency of tests in accordance with Error! Reference source not found. shall
only be specified prior to execution in consultation with the competent planner and the inspection body. This
shall be documented. This shall also apply to the type of tests if it can be verified that deviating test methods
are at least equivalent.
(7) In the event of deficient test results, the contractor shall determine their root cause. If their root cause is
due to the condition of the structure, the competent planner shall be consulted for specification of further
measures.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
(8) Materials that do not meet the requirements shall be sorted out and marked as unsuitable.
(9) Operating equipment in accordance with Section Error! Reference source
not satisfy the requirements shall be marked as unsuitable and must not be used.
not found. that does
5.2 Supervision of substrate priming
5.2.1 Check of concrete compressive strength
The concrete compressive strength of the components to be reinforced shall be checked for plausibility in
non-destructive testing on the component in accordance with DIN EN 13791 within internal control.
5.2.2 Check of the surface tensile strength of the substrate
The surface tensile strength shall be checked in at least 5 locations on the primed substrate in accordance
with DIN EN 1542 using a snap ring groove. After priming of the bond surface, the surface tensile strength of
the concrete shall satisfy the requirements in accordance with Section Error! Reference source not
found. (5).
5.2.3
Check of the concrete cover prior to cutting work performed for reinforcement bonded in
indent cuts
(1) Concrete cover, location and diameter of the reinforcement shall be measured by non-destructive
methods and recorded. Use of the instrument according to the user manual. The accuracy of the instrument
shall be checked, e.g. next to exposed reinforcement or reinforcement to be exposed locally.
(2) Destructive testing of the concrete cover should be conducted in exceptional cases only.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
Table 5.1 – Type, scope and frequency of tests within internal control
Surface reprofiling
Substrate
priming
Step
Test
Visual inspection
Bonding
of CF
sheeting
Bonding of steel tabs
Cuts in
concrete
edge zone
On
concrete
surface
On concrete
surface
Flat sections
on concrete
surface
Angle steel on
concrete
surface
x
x
x
x
x
Surface tensile strength
O
x
x
x
x
Cracks
x
x
x
x
x
Roughness prior to reprofiling
x
x
x
x
x
Surface tensile strength
x
x
x
x
x
Bond strength with substrate
x
x
x
x
x
Compressive strength
x
x
x
x
x
Weather conditions during work
x
x
x
x
x
Moisture
x
x
x
x
x
Temperature
x
x
x
x
x
x
x
x
x
x
Component
surface before
adhesive work
Weather conditions
Adhesive work
Bonding of CFRP
plates
Requirements
Frequency
Suitability of substrate for planned measure
-
Acc. to Chapter Error!
≥ 5 individual tests total;
≥ 1 test per reinforced component/zone
Reference
source not found.
Visual inspection for irregularities or major deviations
from planner’s records; No cracks that could cause
corrosion in the steel reinforcement (see 2.4.1 (3))
≥ 0.5 mm for approved EP mortar and PCC M3;
≥ 1.0 mm for shotcrete or concrete with screed;
≥ 2.5 mm for concrete without screed;
Test in accordance with DIN EN 1766 using sand
surface method or visual inspection with reference
areas;
always in combination with bond tests.
Acc. to Chapter Error!
Reference
source not found.
In accordance with Chapter Error!
Reference source not found.
Acc. to Chapter Error! Reference
source not found.
Product-specific air temperature and humidity and
component temperature and moisture in adhesive
bond zone
Dry according to RiLi SIB or specification in adhesive
approval
Acc. to Chapter Error! Reference
source not found.
Acc. to Chapter Error! Reference
source not found.
-
≥ 1 m²:
3 test for each 50 m²
≥ 5 individual tests total;
≥ 1 test per reinforced component/zone
in accordance with Chapter Error!
Reference source not found.
Acc. to Chapter Error! Reference
source not found.
Daily before work start and if in doubt, e.g.
weather changes
Daily before work start and if in doubt
Daily before work start and if in doubt, e.g.
weather changes
Daily before work start and if in doubt, e.g.
weather changes
Curing test on
component
Steel - adhesive - concrete
O
O
O
x
x
CFRP - adhesive concrete
in accordance with Chapter Error!
in accordance with Chapter Error!
O
x
x
O
O
Reference source not found.
Reference source not found.
Bond test
Adhesive - primer - steel
O
O
O
x
x
Acc. to Chapter Error!
Acc. to Chapter Error!
Quality test
Adhesive
Compressive strength
Tensile strength
x
x
O
x
O
x
O
x
O
x
Pockets in adhesive bond
O
O
O
x
x
Embedding of CFRP plates in indent cuts
x
O
O
O
O
Layer thickness analysis for corrosion
O
O
O
x
x
103
Reference source
not found.
Acc. to Chapter Error!
Reference
source not found.
Acc. to Chapter Error! Reference
source not found.
Acc. to Chapter Error! Reference
source not found.
Acc. to Chapter Error! Reference
Reference
source not found.
Acc. to Chapter Error! Reference
source not found.
Acc. to Chapter Error!
Reference
source not found.
Acc. to Chapter Error! Reference
source not found.
Acc. to Chapter Error! Reference
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Execution
protection
Evenness of bonded tabs/plates
O
x
O
x
x: test required; O: no test required
104
O
source not found.
Acc. to Chapter Error! Reference
source not found.
source not found.
Acc. to Chapter Error! Reference
source not found.
5.3 Check of the reprofiling work
5.3.1 Check of bond strength between reprofiled layer and substrate
(1) For adhesive bonds on large-area additions to the surface using products according to Part 1,
Section 5.9, the bond strength of the concrete substitute in the primed area shall be determined by
adhesive pull test in accordance with DIN EN 1542. The test scope shall be defined according to
DAfStb Guideline ‘Protection and repair of concrete components’, Part 3, Annex A, Line 4.
(2) If concrete substitutes according to RiLi SIB are used for levelling layers, suitability tests and
quality analysis shall be conducted accordingly. In addition to the suitability tests, bond strength tests
shall be conducted to demonstrate the minimum bond strength required for the object. Performance of
these analyses and their documentation are the responsibility of the material inspection body given in
Annex A.
(3) For levelling layers in the anchorage zone according to Part 1, Section 6.2.5, an analysis of the
bond between substrate and levelling layer shall be conducted. Adhesive pull test for bond strength in
accordance with DIN EN 1542 in the edge zone of the concrete addition. The snap ring groove to be
cut shall reach into the existing concrete. Due to higher requirements on the loadbearing capacity of
the addition, the following tests shall be performed:

≥ 5 individual tests total or

≥ 1 for each 50 m bonded plate in the levelling layer zone;

possible additional tests as determined by planner.
(4) The test of bonded reinforcements in the anchorage zone of levelling layers shall result in failure of
the existing concrete. If no failure occurs, the bond strength analysis shall be repeated according to
Part 2 of the Guideline using the measured values.
(5) The test of CFRP plates bonded in indent cuts in the anchorage zone of levelling layers shall result
in failure of the existing concrete. If no failure occurs, the required bond strength analysis shall be
conducted. It shall be performed in accordance with DIN EN 1992 1-1 using the concrete compressive
strength used in static analysis:
-
fctk,surf,is  fctk,surf = fctk,0,05 for concretes up to C50/60.
(6) For small-area levelling layers, the bond strength fctm  shall be 1.5 N/mm2. The test frequency is
specified in DAfStb Guideline ‘Protection and repair of concrete components’, Part 3.
5.3.2 Check of the compressive strength of the reprofiling material
(1) An analysis of the characteristic compressive strength of reprofiling material shall be furnished.
Table 3.2 contains an overview of the requirements on the test specimens.
Table 5.2 – Requirements on the test specimens and test frequency for levelling layers
Levelling layer
Test specimen
Concrete in accordance with DIN 1045-2
Cube 150 mm x 150 mm x
150 mm
Sprayed concrete in accordance with
DIN 18551
Core samples d = 100 mm
from shotcrete slabs
SPCC of strength class M3 in
accordance with RiLi SIB
Core samples d = 50 mm from
shotcrete slabs
PCC of strength class M3 in accordance
with RiLi SIB
V-blocks in accordance with
DIN EN 196-1
Grouting concrete with maximum
particle size 6 mm
V-blocks in accordance with
DIN EN 196-1
Test frequency
According to provisions ÜK 2
of DIN 1045-3
3 V-blocks per batch or per
work day
(2) When using V-blocks in accordance with DIN EN 196-1, the test values Rc shall be converted as
follows for analysis of conformity based on sample specimen geometry according to DAfStb Guideline
“Production and use of cement-bound grouting concrete and grouting mortar”
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
fc,cube = 0.85 x Rc
Conformity assessment shall be carried out in accordance with DIN 1045-2, Section 8.2.1.3, using the
smaller of the values.
Criterion 1:
fc,m ≥ fc,k + 1.48  
Criterion 2:
fc,i  0.9  fc,k
Where
fck
characteristic compressive strength to be assessed in accordance with Section 2.6, Annex 2 in
N/mm2
fcm
mean compressive strength in N/mm 2

Standard deviation of the compressive strength values obtained
fc,i
smallest compressive strength obtained in N/mm 2
5.4
Supervision of the adhesive work
5.4.1 Curing test of the adhesive on the component, with levelling layer, if necessary
(1) The curing of the adhesive bond under climate conditions on the component shall be tested prior to
subjecting it to actions of adhesive pull tests in the layer structure. The test shall be conducted in 5 pull
tests prior to action on the component. If the action on the component is to be applied in steps, a
curing test shall be conducted after each step, at intervals in accordance with Error! Reference
source not found.. The adhesive pull test in accordance with DIN EN 1542 shall result in
concrete failure after adhesive curing.
(2) For surface bonding of CFRP plates, 50 mm x 50 mm sections of the CFRP plate shall be glued to
the concrete using the reinforcement adhesive. The test shall be conducted after creating a snap ring
groove according to DIN EN 1542 that reaches into the substrate.
(3) For surface bonding of CF sheeting, minimum 300 mm x 300 mm sheet sections shall be applied in
the number of layers to be used for component reinforcement. The test shall be conducted on a snap
ring groove according to DIN EN 1542 that reaches into the substrate.
(4) For surface bonding of steel tabs, 50 mm  punched steel pieces shall be glued to the concrete
using the reinforcement adhesive.
(5) If levelling layers are used in the areas of CFRP plates, CF sheeting or steel stabs, the adhesive
pull test shall be performed on the ‘concrete-levelling layer-adhesive-reinforcement element’ system.
5.4.2 Mechanical properties of the adhesive and primer
(1) To verify the mechanical properties of the adhesive and primer used for steel tabs, a quality test
shall assess

the tensile strength of reinforcements bonded to the surface

the tensile and compressive strengths of reinforcement bonded in indent cuts
as laid down in Error!
Reference source not found..
(2) The tensile strength of the adhesive and primer shall be determined in an adhesive pull test using
20 mm  test pieces, which are glued to a Sa 3 blasted steel plate with a thickness of  15 mm and
tested after a curing time of 7 days. The assessment shall be carried out in at least 6 tests per
adhesive batch used or 6 adhesive days each.
(3) The characteristic compressive strength fKc,k of the adhesive shall be obtained on V-blocks in
accordance with DIN EN 196-1 after a curing period of 7 days. The assessment shall be carried out in
at least 3 V-blocks per adhesive batch used or 3 adhesive days each.
Table 5.3 Mechanical characteristics of the adhesive and primer for the quality test under
normal storage conditions 23 °C/50 % R.H.
Property
Characteristic tensile strength fGtk in
N/mm2
106
Criterion 1
Criterion 2
fGtk ≤ fGtm - kn  sGt
fGtk ≤ fGt,i / 0.9
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
fGck ≤ fGcm - kn  sGc
Characteristic compressive strength fGck in
fGck ≤ fGc,i / 0.9
N/mm2
fGtk
fGck
fGtm
fGcm
fGt,i
fGc,i
sGc, sGt
kn
characteristic tensile strength; there is a distinction between the following cases:
a) characteristic tensile strength of the adhesive for plates bonded to a surface: 12 N/mm²
b) characteristic tensile strength of the primer for steel tabs: 12 N/mm²
c) characteristic tensile strength that was assessed in accordance with general building inspectorate
approvals for the design of plates bonded in indent cuts
characteristic compressive strength that was assessed in accordance with general building inspectorate
approvals for the design of plates bonded in indent cuts
mean tensile strength in N/mm2
mean compressive strength in N/mm2
smallest determined tensile strength in N/mm 2
smallest compressive strength obtained in N/mm2
standard deviation of compressive and tensile strengths of the adhesive,
factor according to DIN EN 1990, see Table 3.4
(4) The standard deviation of compressive and tensile strengths of the adhesive shall be obtained as
follows:
sGc 
1 n
 ( f Gc,i  f Gc, m ) 2
(n  1) i 1
(1)
sGt 
1 n
 ( f Gt,i  f Gt,m ) 2
(n  1) i 1
(2)
Table 3.4  values kn
n
6
8
10
20
30
∞
kn
2.18
2.00
1.92
1.76
1.73
1.64
(5) If the material characteristic used in the stability analysis cannot be achieved, this shall be
considered in the subsequent design.
5.4.3 Adhesive bond on pretreated steel
(1) To test the adhesion of the adhesive on the primed steel surface at a room temperature of 20°C, a
minimum of three test pieces of 20 mm in  shall be glued to a 15 mm thick steel plate or a steel
section of equivalent stiffness and pulled off. The characteristic adhesive pull strength fKt,k ≥ 12 N/mm2
shall be reached in a test after 7 days.
(2) The steel plate shall be pre-treated in the same manner as the steel tabs (see sections 2.6.2 (3) to
(5)).
5.5
Checks after execution
(1) The evenness of the surface-bonded plates or sheets shall be checked immediately upon removal
of any supports used. On a test section of 300 mm, the deviation from the flat surface shall not exceed
Δh = 1 mm.
(2) One-way curvatures that push plates or sheeting against the concrete are acceptable.
(3) Bonded steel tabs shall be checked for hollow spaces after curing of the adhesive. If there are
hollow spaces in the end zone or more than three defective spots in the middle zone, the tab shall be
removed. If there are hollow spaces in other zones or less than 3 hollow spaces, they may be filled
pressureless with crack filling material on epoxy resin basis in accordance with DIN EN 1504-5 in
combination with DIN V 18028 according to the provisions in RiLi SIB.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
(4) The complete embedding of the CFRP plates bonded in indent cuts shall be checked. Areas of the
plate with bondless areas of more than 5 % of the plate sectional area shall subsequently be taken
into account in the design.
5.6
Corrosion protection work
(1) The thickness of the effective corrosion protection on steel parts shall be assessed on the
component by non-destructive methods. The provisions of DIN EN ISO 12944-7 shall apply.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
Annex A Permanent inspection body (normative)
(1) The contractor shall have a permanent inspection body in place in the event of

installation of concretes of monitoring classes 2 and 3;

installation of concrete substitution systems for large-scale additions to concretes of monitoring
classes 2 and 3 (definitions in the meaning of DIN 1045-3, Table 3);

production of surfaces of parking areas subject to direct traffic including wear layers;

reinforcement of components with concrete in accordance with DIN 1045 or shotcrete in
accordance with DIN 18551;

manufacture of components with adhesive bond reinforcement;
(2) The permanent inspection body shall

be equipped with all equipment and devices to conduct the tests in accordance with Section 1.3.

be headed by a skilled individual experienced in concrete technology and the maintenance of
concrete components, who is able to provide verification of advanced knowledge in concrete
technology (E-certificate) and knowledge in the areas of protection, repair and reinforcement of
components (German designation of certificate: SIVV -Schein).

If the materials inspection body is involved in the assessment of the building material with regard
to the reinforcement by adhesive bonding, the representative of the inspection body shall be
certified as a qualified manager for bonded component reinforcements in accordance with Annex
D by a recognised inspection body.
(3) The contractor or the head of the concrete inspection body are responsible for regular training of
their skilled personnel and keeping records of such training.
(4) If a contractor uses an external inspection body, any inspection tasks shall be transferred to the
inspection body by written agreement. Such agreement shall have a minimum validity of one year. The
contractor may not hire an inspection body that also monitors the manufacturer of the concrete or
concrete substitution systems or of which it is financially dependent.
(5) The permanent inspection body has the following tasks:

provide consulting to the contractor and construction sites;

perform tests according to Section 3, unless conducted by site personnel;

check equipment on site prior to start of the work;

continuous checks and advice on processing and after-treatment of concrete or concrete
substitution systems as well as surface protection systems and reinforcement measures in
accordance with Paragraph (1). The results of these checks shall be recorded;

assessment and evaluation of the test results in accordance with section 3 and reporting of the
results to the contractor and its supervisors;

training of the skilled site personnel.
109
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
Annex B Test methods during execution (normative)
(1) The surface of the substrate in the reinforcement zone shall be inspected visually for

defective spots such as pits, burrs and irregularities, loose particles and concrete chipping,
especially above the reinforcement;

moisture, efflorescence, crystallisation, or growth;

contamination by foreign materials, e.g. oil, grease, old coatings.
(2) Hollow spots near the surface may be detected by differences in sound obtained by tapping.
(3) The test of the substrate moisture content is qualitative according to RiLi SIB with classification of
moisture states as “dry”, “moist” and “wet”. The quantitative determination of the concrete’s moisture
content may be carried out with the CM devices and assessed in accordance with RiLi SIB. Other test
methods for determining the moisture content of concrete are permissible, provided their results are of
equivalent relevance.
(4) Determination of substrate roughness shall be carried out in accordance with DIN EN 1766, using
the Kaufmann method of measurement.
(5) The surface tensile strength of the substrate and the bond strength between the substrate and
individual layers shall be determined in accordance with DIN EN 1542. The test locations shall be
predrilled to reach into the substrate.
(6) Cracks that might result in corrosion of existing steel reinforcements shall be recorded in
accordance with RiLi SIB.
(7) Measurement of air temperature and humidity as well as surface temperature and determination of
dew point temperature shall be carried out in accordance with RiLi SIB.
110
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
Annex C Supervision of work by an accredited inspection
body (normative)
(1) The execution of the levelling layers and adhesive work governed by this Guideline are stabilityrelevant measures. In addition to a monitoring duty of the contractor, there exists a monitoring duty for
the inspection bodies listed in the “Verzeichnis der Prüf-, Überwachungs- und Zertifizierungsstellen
nach den Landesbauordnungen”, [Listing of testing, monitoring and certification bodies according to
state construction regulations, Part V, No 7].
(2) The provisions of this Guideline and DAfStb Guideline ‘Protection and repair of concrete
components’, Part 3 shall apply to the monitoring and execution.
(3) The following documentation shall be made available to the inspection body upon request:

planner and auditor of the static analysis;

test results on the actual condition of the component to be reinforced;

daily reports on reinforcement;

delivery notes for products used (adhesive, primer, repair mortar, plates);

contractor’s qualification certificates (suitability certificate, ‘SIVV-Schein’);

layout plan and properties of the bonded CFRP plates and CF sheeting;

results of execution monitoring (see Section Error! Reference source not found.).
111
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
Annex D Certificate of suitability for contractors for
reinforcement of concrete components using adhesive
bonding (normative)
D.1
General
(1) Any contractor that executes component reinforcements according to this Guideline shall provide
proof of its qualification in the form of a certificate of suitability for reinforcement of components using
adhesive bonding.
(2) Certificates of suitability are granted by certified inspection bodies listed in the Annex to this
Guideline. Certificates of suitability may be granted for

reinforcement of CFRP plates and steel tabs by bonding to a component surface (see Section D
3.1);

reinforcement using CFRP plates and steel tabs by gluing them on the component surface or
gluing CFRP plates into indent cuts (see Section D 3.2);

reinforcement through lamination of CF sheeting to the component surface for confinement
purposes (see Section D 3.3);

reinforcement through lamination of CF sheeting to the component surface for flexural tensile
reinforcement (see Section D 3.4).
(3) The suitability test includes the initial inspection of the operation and its skilled personnel in
1
practical suitability tests including monitoring by an accredited inspection body . The suitability
certifications are deemed satisfied if the organisation submits the certificate issued by the inspection
body on its suitability for reinforcement of concrete components, where the certificate applies to the
respective type of adhesive bonding (see (2)).
(4) Certificates issued prior to entry into force of this Guideline shall be recognised.
D.2
Formal requirements for the operation and the skilled personnel
(1) The initial test by the inspection body shall assess whether the personnel and technical conditions
for proper reinforcement and their monitoring have been satisfied.
2) The operation shall have on staff a qualified manager in accordance with DAfStb Guideline
‘Protection and repair of concrete components’, Part 3, possessing special knowledge in the area of
testing, processing and repair of concrete components and the use of resin products for loadbearing
adhesive bonding.
(3) Only skilled site personnel possessing special knowledge and skills in the area of repair of
reinforced concrete components in accordance with DAfStb Guideline ‘Protection and repair of
concrete components’, Part 3, may take part in the suitability test; they shall demonstrate their skills in

substrate priming;

corrosion protection of the reinforcement;

use of repair concretes and mortars;

filling of cracks;

use of adhesives and reinforcement elements in concrete construction.
(4) The basic capability to work in accordance with general building inspectorate approvals shall be
furnished as proof to the inspection body by means of the respective certificate. This evidence may be
furnished in the form of a certificate for “using plastics in concrete construction” [“Verarbeiten von
Kunststoffen im Betonbau” (SIVV-Schein)] from Deutscher Beton und Bautechnik-Verein e. V.
(5) The company shall provide evidence that the skilled personnel is trained at intervals of no more
than three years on protection and repair measures, especially reinforcement measures using
adhesive bonding, in accordance with valid general building inspectorate approvals to enable them to
safely carry out proper execution of adhesive work including the necessary tests.
1
See Part IV of the directory of testing, monitoring and certification bodies according to state construction
regulations, No 8, last: “Mitteilungen des Deutschen Institut für Bautechnik 41 (2010), Sonderheft 40”
112
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
(6) During the initial assessment of the organisation, the inspection body will evaluate the
completeness and status of the test and measuring equipment as well as tools and mixing devices
that are necessary for work according to general building inspectorate approvals. The inspection body
will review the contractor’s monitoring process for completeness and satisfaction of requirements of
general building inspectorate approvals.
(7) The relevant instruments for determining the adhesive pull strength are subject to regular function
and accuracy inspections. The results of these inspections shall be documented.
D.3
Suitability tests
D 3.1 General requirements
(1) The characteristic values obtained during the following suitability tests shall be documented and
statistically analysed in accordance with specifications of a valid general building inspectorate
approval by the contractor or the material inspection body.
(2) The adhesive bond shall be executed taking into account this Guideline and the execution-relevant
sections of a valid general building inspectorate approval. The monitoring report of the contractor and
the records of the personnel performing the work shall be checked.
(3) Suitability shall be recognised if flawless adhesive bonds and relevant results in accordance with a
valid general building inspectorate approval have been achieved. The suitability tests may only be
repeated in their entirety per reinforcement type.
D 3.2 Reinforcement by bonding CFRP plates and steel tabs to the component
surface
(1) For reinforcement using CFRP plates and steel tabs bonded to the surface of a component, a
reinforced concrete beam made from C 30/37, 4 m in length and minimum 400 mm in height shall be
reinforced at a height of 3 m. Substrate priming for adhesive bonding shall be conducted in line with
the execution-relevant sections of a general building inspectorate approval for surface-bonded CFRP
plates and this Guideline. The monitoring report of the contractor and the records of the personnel
performing the work shall be checked.
(2) Two steel tabs and two CFRP plates as longitudinal tensile strength reinforcement shall be bonded
to the bottom side of the reinforced concrete beam located at 3 m height. Additionally, 2 steel tab links
consisting of two L-shaped parts shall provide the shear reinforcement. Of the two steel tabs for
longitudinal reinforcement, one should be dimensioned 100 mm x 10 mm x 3 500 mm and the other
200 mm x 10 mm x 3 500 mm. The CFRP plates for longitudinal reinforcement shall be different in
width and 3 500 mm long. The width of the steel tabs for shear reinforcement shall be 100 mm. The
leg length of the two L-shaped parts shall be selected so that in the bonded state, they will enclose the
beam width and height of the concrete beam to be reinforced.
(3) Prior to applying the wider steel tab and the wider CFRP plate for longitudinal reinforcement, the
concrete cover shall be chiselled down to the reinforcement in the mid zone of the adhesion surface to
create a defective spot. The defective spot shall be repaired using reprofiling mortar in accordance
with Section 2.5 of this Guideline.
(4) Upon curing of the adhesive, the steel tab links and then the steel tabs for longitudinal
reinforcement shall be pried off. The adhesive bond shall then be assessed. There should be
complete concrete failure in the areas bonded to the concrete, both in the steel tab link and the steel
tabs for longitudinal reinforcement.
(5) The evaluation of the bond of the CFRP plates for longitudinal reinforcement shall be conducted
after curing of the adhesive by means of pull-off tests. Prior to the pull-off test, snap ring grooves with
an inner diameter of 50 mm or square grooves of 50 mm side length shall be drilled or cut into the
concrete, or the plate shall be cut cross-wise at a width that is equivalent to the diameter of the test
piece. The test pieces shall be glued to the CFRP plates inside the grooves or the cut joint. Five pulloff tests shall be conducted, with a minimum of 2 tests on each CFRP plate. Here the concrete failure
shall be complete.
D 3.3 Reinforcement by bonding CFRP plates, steel tabs to the component surface and by
CFRP plates bonded in indent cuts
(1) The following assessment shall be furnished in addition to the assessments in D 3.1.
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DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
(2) A reinforced concrete slab located at a height of 3 m or a reinforced concrete beam located at a
height of 3 m that is at least 4 m long can be a component for longitudinal reinforcement with CFRP
plates bonded in indent cuts. In both cases, the concrete strength class shall be C30/37. For this, 2
indents are cut and 2 CFRP plates glued into them. The minimum length of the CFRP plates shall be
3500 mm.
(3) Prior to cutting the indents in the concrete cover of the reinforced concrete part, a baseline
measurement of reinforcement on the entire area to be reinforced shall be conducted by a nondestructive method. All measurements shall be conducted in accordance with the Annex to DBF Code:
“Concrete Cover and Reinforcement” [German designation: DBV-Merkblatt “Betondeckung und
Bewehrung”] The measuring results shall be checked by exposing the reinforcement in at least one
spot.
D 3.4 Reinforcement by laminating CF sheeting to the component surface for confinement
(1) For reinforcement using CF sheeting bonded to the surface of a component, a reinforced concrete
beam made from C 30/37, 4 m in length and minimum 400 mm in height with shear reinforcement and
two well rings with a minimum diameter of 1.5 m and 40 cm height shall be reinforced. If suitability
tests in accordance with 3.1 were conducted before, the beams mentioned under 3.1 may be used
again for shear reinforcement. All bonded CFRP plates or steel tabs shall first be removed. Substrate
priming for lamination shall be carried out in accordance with the respective sections of a valid general
building inspectorate approval for reinforcement by laminating CFRP plates onto a component surface
and this Guideline. The monitoring report of the contractor and the records of the personnel
performing the work shall be checked.
(2) Two strips of the sheeting shall be laminated as shear reinforcement onto the reinforced concrete
beam that is located at a height of 3 m. One of the shear reinforcement strips shall consist of one layer
and the other of three layers. The width of the shear reinforcement shall be 100 mm. The shear
reinforcement shall enclose the entire beam. The well rings shall be wrapped in sheeting strips over
their entire height. One well ring shall be covered with one layer of sheeting and the second one with
three layers of sheeting.
(3) Prior to laminating, the concrete cover in the lower mid area of the adhesive surface of a shear
reinforcement and midway on the well rings shall be chiselled away down to the reinforcement to
create defective spots. The defective spots shall be repaired using reprofiling mortar in accordance
with section 2.5 of this Guideline.
(4) The assessment of the adhesive bond of the CFRP sheeting shall be conducted by pull-off tests
after curing of the laminating resin. Prior to the pull-off test, snap ring grooves with an inner diameter
of 50 mm shall be drilled into the CFRP sheeting or square grooves of 50 mm side length shall be cut
into the concrete. The test pieces shall be glued to the CF sheeting inside the groove. Five pull-off
tests shall be conducted, with a minimum of one test on each CFRP sheet (shear reinforcement and
confinement layers). Here the concrete failure shall be complete.
D 3.5 Reinforcement by laminating CF sheeting to the component surface for flexural tensile
reinforcement
(1) For reinforcement using CF sheeting bonded to the surface of a component, a reinforced concrete
beam made from C 30/37, 4 m in length and minimum 400 mm in height shall be reinforced at a height
of 3 m. If suitability tests according to 3.1 were conducted, the beams may be used again. All bonded
CFRP plates or steel tabs shall first be removed. Substrate priming for lamination shall be carried out
in accordance with the respective sections of a valid general building inspectorate approval for
reinforcement by laminating CFRP plates onto a component surface and this Guideline. The
monitoring report of the contractor and the records of the personnel performing the work shall be
checked.
(2) Two sheeting strips as longitudinal reinforcement and two sheeting strips as shear reinforcement
shall be laminated to the bottom side of the reinforced concrete beam located at 3 m height. One of
each strip, both for longitudinal and shear reinforcement, shall consist of one layer and the other of
three layers. The longitudinal reinforcements shall be different in width and 3 500 mm long. The width
of the shear reinforcement shall be 100 mm. The shear reinforcement shall enclose the entire beam.
(3) Prior to laminating, the concrete cover in the lower mid area of the adhesive surface shall be
chiselled away down to the reinforcement to create defective spots.
(4) The assessment of the adhesive bond of the CFRP sheeting shall be conducted by pull-off tests
after curing of the laminating resin. Prior to the pull-off test, snap ring grooves with an inner diameter
114
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 3: Construction
of 50 mm shall be drilled or square grooves of 50 mm side length shall be cut into the concrete. The
test pieces shall be glued to the CF sheeting inside the groove. Five pull-off tests shall be conducted,
with a minimum of one test on each CFRP sheet (longitudinal and shear reinforcement). Here the
concrete failure shall be complete.
D.4
Certification of the contractor
(1) The inspection body shall issue a certificate of suitability for the contractor if proof of suitability has
been furnished. A copy of this certificate and the corresponding evaluation reports shall be sent to the
German Institute of Structural Engineering.
(2) The certificate is issued for a period of three years and is revocable. Upon request, the validity
period of the certificated may be renewed for three years. Prior to each renewal, it shall be
demonstrated to the inspection body that the conditions of the general building inspectorate approvals
have been satisfied. The contractor shall report any changes in personnel responsible to the
inspection body.
(3) Upon expiry of the certification period, the inspection body may extend the suitability certificate. To
do so, the contractor shall submit a list of construction projects carried out, including the following
information:

Name, location and type of construction project;

Supervision report on the execution by the inspection body.
115
DEUTSCHER AUSSCHUSS FÜR
(GERMAN
COMMITTEE
FOR
CONCRETE)
STAHLBETON
REINFORCED
DafStb Guideline on
Available from Beuth Verlag GmbH, Berlin, sales number 650XX
on the reinforcement of concrete parts
with adhesive bonding
Part 4: Additional rules for planning reinforcement measures
Draft March 2012
The requirements of Directive 98/34/EC of the European Parliament and of the Council of 22 June
1998 laying down a procedure for the provision of information in the field of technical standards and
regulations and of rules on Information Society services (OJ L 204 of 21 July 1998, p. 37), recently
amended by Directive 2006/96/EC (OJ L 363 of 20 December 2006, p. 81) have been taken into
account.
Regarding the standards, other documents and technical specifications related to products or test
procedures named in this Guideline, the rule is that other products and test procedures may be
applied if they meet the standards and other provisions and/or technical specifications of other EU
Member States, Turkey or other EFTA State, that is a Contract State of the European Economic Area
(EEA), provided the specified level of protection with regard to safety, health and suitability of use is
equally permanently achieved.
Published by:
Deutscher Ausschuss für Stahlbeton e. V. (DAfStb)
Budapester Straße 31
D – 10787 Berlin-Tiergarten
Phone: 030 2693-1320
info@dafstb.de
The Deutsche Ausschuss für Stahlbeton (DAfStb) retains all rights, including translation into foreign languages. This document or any
part thereof may not be photocopied or otherwise reproduced without the explicit permission of DAfStb.
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 4: Additional rules for planning reinforcement measures
Contents List Part 4
1 Scope of application ................................................................................................. 117
2 Normative references ................................................................................................ 117
3 Requirements of the component to be reinforced................................................ 117
3.1 Special regulations for steel tabs, CFRP plates and CF sheeting bonded to a
surface....................................................................................................................117
3.2 Special rules for CFRP plates bonded in indent cuts .........................................117
4 Principles .................................................................................................................... 118
4.1 General ...................................................................................................................118
Annex A Determination of the expected mean value ............................................ 119
117
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 4: Additional rules for planning reinforcement measures
1 Scope of application
(1) This part of the Guideline establishes rules for the planning of reinforcement measures of parts
using adhesive bonding.
(2) If repair of a component is necessary as part of a reinforcement measure, the DAfStb Repair
Guideline shall also apply.
(3) Application of this Guideline in areas subject to building inspectorate approval shall require a
general building inspectorate approval as usability verification of the reinforcement systems.
(4) Planning of reinforcement measures includes an assessment of the actual state.
(5) Prior to start of the measures, satisfaction of requirements on the component to be reinforced shall
be examined and documented.
(6) If concrete covers in accordance with DIN EN 1992-1-1 for inner reinforcement are not satisfied,
additional measures may be necessary to ensure endurance, taking account the residual life span.
2 Normative references
DIN EN 1542, Products and systems for the protection and repair of concrete structures – Test
methods – Measurement of bond strength by pull-off
DIN EN 1992-1-1, Eurocode 2: Design of concrete structures - Part 1-1: General – Common rules for
building and civil engineering structures
DIN EN 13791, Assessment of in-situ compressive strength in structures and precast concrete
components
DAfStb Guideline ‘Protection and repair of concrete components’ (‘Schutz und Instandsetzung von
Betonbauteilen’), 2001 edition
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding - Part 1: Design and
construction
3 Requirements of the component to be reinforced
3.1 Special regulations for steel tabs, CFRP plates and CF sheeting
bonded to a surface
(1) The necessary surface tensile strength of the concrete in accordance with Part 1 of this Guideline
shall be determined on the component.
(2) Flatness characteristics shall be checked on the component.
(3) It shall be checked that there is no concave curvature in the area of the planned adhesive bond
area. The primed substrate shall not exceed tolerances of 5 mm per 2 000 mm.
(4) In the adhesive bond area, the minimum concrete cover of the steel reinforcement shall be 10 mm
to ensure transmission of the bond forces of the adhesive bond.
3.2 Special rules for CFRP plates bonded in indent cuts
(1) Large-area unevenness up to 30 mm shall be levelled by grinding or a suitable mortar system.
(2) An analysis of the concrete cover in the area of the plates to be bonded in indent cuts shall be
conducted and the results documented. The assessed concrete cover shall at minimum equal the
plate width increased by the allowance in design for deviation (see detailing arrangements in Part 1 of
this Guideline).
118
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 4: Additional rules for planning reinforcement measures
4 Principles
4.1 General
(1) Planning according to this Guideline shall entail at minimum:

Determination and assessment of the condition of the component to be reinforced (actual state,
possibly cause of damage and prognosis).

Assessment of the structural safety including statement regarding stability, serviceability,
durability and fire protection;

Statements on the accessibility of the components to be reinforced;

Definition whether the reinforcement measure is relevant to stability or for the purpose of
serviceability;

Statements on expected future corrosion on the inner reinforcement during the residual life span
of the component in the area of the bonded reinforcement;

Specification of potential additional protective measures;

Specification of potentially required maintenance and repair after reinforcement of a component;

Structural analysis of the reinforcement in accordance with Part 1 of this Guideline;

A layout plan with specification of the properties of the adhesive system.
(2) Data on the properties of the concrete component to be reinforced originating from existing
documentation may be used upon expert evaluation in the planning draft.
(3) Data on the actual state of the component to be reinforced required for further planning of the
reinforcement measure shall entail the following:

the mean surface tensile strength of the concrete in the bonded areas, determined in accordance
with DIN EN 1542. The mean value fctm,surf used in design shall not exceed the expected mean
value obtained on the component. The expected mean value shall be obtained as a function of
the number of random samples and the standard deviation according to Annex A.

The concrete compressive strength of each component section to be reinforced, determined
according to DIN EN 13791;

type and condition of the existing reinforcement;

concrete cover of the existing reinforcement and carbonation depth in the concrete;

location, course and width of cracks, if these might cause corrosion on the inner reinforcement;

if applicable, data on harmful substances in the concrete that might cause corrosion of the
reinforcement or concrete;
(4) If the concrete cover of the existing inner reinforcement does not satisfy the requirements of DIN
EN 1992, additional measures for ensuring corrosion and fire protection before or after carrying out the
bonding work shall be planned.
119
DAfStb Guideline on the reinforcement of concrete parts with adhesive bonding –
Part 4: Additional rules for planning reinforcement measures
Annex A Determination of the expected mean value
(1) The expected mean value shall be determined based on the number of tests and the standard
deviation in accordance with Equation (A.1).
1 n 
f m     f i   k  s
 n i 1 
(A. 1)
Where:
fm
n
fi
k
s
expected mean value
number of random samples
value of individual random samples
value according to Table A.1
standard deviation of the random samples
Table A.1: Factor k
Column
Line
1
2
3
4
5
6
7
8
9
10
11
12
1
n
5
6
7
8
9
10
15
20
25
30
35
2
k
0.953
0.823
0.734
0.670
0.620
0.580
0.455
0.387
0.342
0.310
0.286
k
t n 1;1S;
n
Calculated for one side for statistical confidence of S
= 95 %; t from student distribution
120