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ACI 506.2-13
An ACI Standard
Reported by ACI Committee 506
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Specification for Shotcrete
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American Concrete Institute®
Advancing concrete knowledge
Specification for Shotcrete
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ACI 506.2-13
Specification for Shotcrete
An ACI Standard
Reported by ACI Committee 506
Lawrence J. Totten, Chair
Jon B. Ardahl*
Lars Balck, Jr.
Michael Ballou
Nemkumar Banthia
Chris D. Breeds
Wern-Ping Nick Chen
Scott R. Cumming*
Jean-Francios Dufour
Jill E. Glassgold
Charles S. Hanskat*
Warren L. Harrison
Marc Jolin*, Secretary
Thomas Hennings
Kristian Loevlie
Mark R. Lukkarila
Gregory S. McKinnon
Jeffrey L. Novak
H. Celik Ozyildirim
Harvey W. Parker
Ryan E. Poole
John H. Pye
James A. Ragland*
Venkataswamy Ramakrishnan
Raymond C. Schallom, III
Raymond J. Schutz
Philip T. Seabrook†
W. L. Snow, Sr.*
Peter C. Tatnall*
Curtis White
Peter T. Yen
George Yoggy
Lihe Zhang
Christopher M. Zynda
Task group members who produced this specification.
Task group Chair who produced this specification.
Consulting members
Merlyn Isaak
Richard A. Kaden
Roman Malinowski
Dudley R. Morgan
CONTENTS
(mandatory portion follows)
*
†
PART 1—GENERAL, p. 2
1.1—Scope, p. 2
1.2—Definitions, p. 2
1.3—Referenced standards, p. 2
1.4—Submittals, p. 3
1.5—Preconstruction testing by Contractor, p. 4
1.6—Testing during construction, p. 4
1.7—Delivery, storage, and handling, p. 5
This specification contains the construction requirements for the
application of shotcrete. Both wet- and dry-mixture shotcrete are
addressed, as well as fiber-reinforced shotcrete. The minimum standard for materials, properties, testing, and application are covered.
The materials, processes, quality control measures, and inspections described in this specification should be tested, monitored,
or performed as applicable only by individuals holding the appropriate ACI certifications or equivalent.
Keywords: dry-mixture shotcrete; fiber-reinforced shotcrete; nozzleman;
qualification; quality control; quality assurance; shooting; wet-mixture
shotcrete.
PART 2—PRODUCTS, p. 5
2.1—Materials, p. 5
2.2—Packaged shotcrete materials, p. 5
2.3—Fiber-reinforced shotcrete, p. 5
2.4—Shotcrete properties, p. 5
2.5—Proportioning, p. 6
2.6—Batching, mixing, and delivery, p. 6
PART 3—EXECUTION, p. 6
3.1—Preparation of surface to receive shotcrete, p. 6
3.2—Joints, p. 6
3.3—Alignment control, p. 6
3.4—Application, p. 6
ACI Committee Reports, Guides, and Commentaries are
intended for guidance in planning, designing, executing, and
inspecting construction. This document is intended for the use
of individuals who are competent to evaluate the significance
and limitations of its content and recommendations and who
will accept responsibility for the application of the material it
contains. The American Concrete Institute disclaims any and
all responsibility for the stated principles. The Institute shall
not be liable for any loss or damage arising therefrom.
Reference to this document shall not be made in contract
documents. If items found in this document are desired by
the Architect/Engineer to be a part of the contract documents,
they shall be restated in mandatory language for incorporation
by the Architect/Engineer.
ACI 506.2-13 supersedes ACI 506.2-95 and was adopted on October 29, 2013 and
published in January 2014.
Copyright © 2014 American Concrete Institute
All rights reserved including rights of reproduction and use in any form or by any
means, including the making of copies by any photo process, or by electronic or
mechanical device, printed, written, or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval system or device, unless permission in
writing is obtained from the copyright proprietors.
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Subcommittee member
Donald M. McPhee
1
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
3.5—Finish, p. 7
3.6—Curing, p. 7
3.7—Protection, p. 8
3.8—Tolerances, p. 8
3.9—Repair of shotcrete, p. 8
3.10—Acceptance of Work, p. 8
(nonmandatory portion follows)
NOTES TO SPECIFIER, p. 8
General notes, p. 8
FOREWORD TO CHECKLISTS, p. 9
CHECKLIST REFERENCES, p. 12
(mandatory portion follows)
PART 1—GENERAL
1.1—Scope
1.1.1 Work specified—This Reference Specification covers
the requirements for shotcrete as specified by the Architect/Engineer. Included are the requirements for materials;
proportioning; and application of structural and nonstructural shotcrete, including structural and nonstructural fiberreinforced shotcrete.
1.1.2 Units—Values in this specification are stated in inchpound units. A companion specification in SI units is also
available.
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1.2—Definitions
accepted—determined to be satisfactory by Owner or
Architect/Engineer.
Architect/Engineer—the architect, engineer, architectural firm, engineering firm, or architectural and engineering
firm issuing Contract Documents or administering the Work
under Contract Documents, or both.
Contract Documents—set of documents supplied by
Owner to Contractor as the basis for construction; these
documents contain contract forms, contract conditions,
specifications, drawings, addenda, and contract changes.
Contractor—the person, firm, or corporation with whom
the Owner enters into an agreement for construction of the
Work.
fiber-reinforced shotcrete (FRS)––shotcrete containing
discontinuous discrete fibers.
gun finish––undisturbed final layer of shotcrete as applied
from a nozzle without further finishing.
overspray—waste shotcrete material deposited away
from intended receiving surface.
Owner—the corporation, association, partnership, individual, public body, or authority with whom the Contractor
enters into an agreement and for whom the Work is provided.
permitted—accepted by or acceptable to Architect/Engineer; usually pertains to a request by Contractor, or when
specified in Contract Documents.
predampening—in the dry-mixture process, adding
water to the aggregate before mixing to bring its moisture
content to a specified amount, usually 3 to 6 percent.
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quality assurance—actions taken by Owner or Owner’s
representative to assure Work done and materials provided
are in accordance with Contract Documents.
quality control—actions taken by the Contractor to assure
that Work meets requirements of Contract Documents.
Reference Specification—a standardized mandatorylanguage document prescribing materials, dimensions,
and workmanship, incorporated by reference in Contract
Documents.
Reference
Standards—standardized
mandatorylanguage documents of a technical society, organization, or
association, including building codes of local or state authorities, which are referenced by the Contract Documents.
required—stipulated in this specification or the Contract
Documents.
rod finish––a sharp-edged cutting screed to be used to
trim shotcrete forms or ground wires.
shotcrete—concrete or mortar conveyed through a hose
and pneumatically projected at high velocity onto a surface
to achieve compaction.
structural shotcrete—plain or reinforced shotcrete in a
member that is part of a structural system required to transfer
gravity and/or lateral loads along a path to the ground.
submit—provide to Architect/Engineer for review.
submittal—documents or materials provided to Architect/Engineer for review and/or acceptance.
Work—the entire construction or separately identifiable parts thereof required to be furnished under Contract
Documents.
1.3—Referenced standards
Standards of ASTM International cited in this Specification are listed by name and designation, including year.
ASTM International
A185/A185M-07—Standard Specification for Steel
Welded Wire Reinforcement, Plain, for Concrete
A615/A615M-12—Standard Specification for Deformed
and Plain Carbon-Steel Bars for Concrete Reinforcement
A706/A706M-09b—Standard Specification for LowAlloy Steel Deformed and Plain Bars for Concrete
Reinforcement
C33/C33M-13—Standard Specification for Concrete
Aggregates
C78/C78M-10e1—Standard Test Method for Flexural
Strength of Concrete (Using Simple Beam with Third Point
Loading
C42/C42M-13—Standard Test Method for Obtaining and
Testing Drilled Cores and Sawed Beams of Concrete
C94/C94M-13a—Standard Specification for ReadyMixed Concrete
C127-12—Standard Test Method for Density, Relative Density (Specific Gravity), and Absorption of Coarse
Aggregate
C128-12—Standard Test Method for Density, Relative Density (Specific Gravity), and Absorption of Fine
Aggregate
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
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C150/C150M-12—Standard Specification for Portland
Cement
C171-07—Standard Specification for Sheet Materials for
Curing Concrete
C231/C231M-10—Standard Test Method for Air Content
of Freshly Mixed Concrete by the Pressure Method
C309-11—Standard Specification for Liquid MembraneForming Compounds for Curing Concrete
C494/C494M-13—Standard Specification for Chemical
Admixtures for Concrete
C457/C457M-12—Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in
Hardened Concrete
C618-12a—Standard Specification for Coal Fly Ash and
Raw or Calcined Natural Pozzolan for Use in Concrete
C642-13—Standard Test Method for Density, Absorption,
and Voids in Hardened Concrete
C685/C685M-11—Standard Specification for Concrete
made by Volumetric Batching and Continuous Mixing
C928/C928M-09—Standard Specification for Packaged,
Dry, Rapid-Hardening Cementitious Materials for Concrete
Repairs
C989/C989M-12a—Standard Specification for Slag
Cement for Use in Concrete and Mortars
C1059/C1059M-99 (2008)—Standard Specification for
Latex Agents for Bonding Fresh to Hardened Concrete.
C1064/C1064M-12—Standard Test Method for Temperature of Freshly Mixed Hydraulic -Cement Concrete
C1077-13b—Standard Practice for Laboratories Agency
Testing Concrete and Concrete Aggregates for Use in
Construction and Criteria for Testing Agency Evaluation
C1116/C1116M-10a—Standard Specification for FiberReinforced Concrete
C1140/C1140M-11—Standard Practice for Preparing and
Testing Specimens from Shotcrete Test Panels
C1141/C1141M-08—Standard Specification for Admixtures for Shotcrete
C1240-12—Standard Specification for Silica Fume Used
in Cementitious Mixtures
C1315-11—Standard Specification for Liquid MembraneForming Compounds Having Special Properties for Curing
and Sealing Concrete
C1385/C1385M-10—Standard Practice for Sampling
Materials for Shotcrete
C1399/C1399M-10—Standard Test Method for Obtaining
Average Residual-Strength for Fiber-Reinforced Concrete
C1436-08—Standard Specification for Materials for
Shotcrete
C1480/C1480M-12—Standard Specification for Packaged, Pre-Blended, Dry, Combined Materials for Use in Wet
or Dry Shotcrete Application
C1550-12a—Standard Test Method for Flexural Toughness of Fiber Reinforced Concrete (Using Centrally Loaded
Round Panel)
C1583/C1583M-13—Standard Test Method for Tensile
Strength of Concrete Surfaces and the Bond Strength or
Tensile Strength of Concrete Repair and Overlay Materials
by Direct Tension (Pull off Method)
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C1602/C1602M-12—Standard Specification for Mixing
Water Used in the Production of Hydraulic Cement Concrete
C1604/C1604M-05(2012)—Standard Test Method for
Obtaining and Testing Drilled Cores of Shotcrete
C1609/C1609M-12—Standard Test Method for Flexural
Performance of Fiber-Reinforced Concrete (Using Beam
with Third-Point Loading)
1.4—Submittals
1.4.1 Submit data showing compliance with requirements
specified in 1.4.1.1 through 1.4.1.17. Where available,
submit material safety data sheets (MSDS) for all materials.
1.4.1.1 Submit shotcrete mixture proportions. Submittals
shall show constituent proportions by mass in the case of
batching by weight or proportions by volume in the case of
volumetric batching. For prepackaged materials meeting
ASTM C1480/C1480M, submit suppliers’ technical data
showing compliance with requirements.
1.4.1.2 Submit compressive strength test results and,
if fiber-reinforced shotcrete (FRS) is specified, flexural
strength and flexural parameters in accordance with the
Contract Documents.
1.4.1.3 Submit water-cementitious materials ratio (w/cm)
for wet-mixture shotcrete only.
1.4.1.4 Submit admixture types, brand names, producers,
manufacturer’s technical data sheets describing technical
properties and performance in shotcrete and showing
compatibility with the project cementitious materials.
1.4.1.5 Submit cementitious materials types, test reports
showing manufacturing location, and compliance with
applicable ASTM standards.
1.4.1.6 Submit aggregate source, producers’ names, gradations, specific gravities, compliance with ASTM C33/C33M,
and evidence that this data is not more than 1 year old.
1.4.1.7 Submit aggregate absorption in accordance with
ASTM C127 for coarse aggregate and ASTM C128 for fine
aggregate.
1.4.1.8 Submit qualifications and experience of the
proposed workers including the supervisor, nozzlemen, and
crew. For structural or FRS shotcrete, submit evidence of
ACI certification of nozzlemen proposed for the Work.
1.4.1.9 For application of structural shotcrete, submit
proof of experience for the Contractor and the shotcrete
crew foreman to include at least five projects of similar size
and complexity. Proof shall include a description of previous
project’s size; density of reinforcing materials; volume of
shotcrete placed; and the name, address, and current phone
number of person(s) representing the Owner or Architect/
Engineer. For other applications of shotcrete, submit proof
that the Contractor and crew foreman have at least 3 years’
experience in that type of shotcrete application.
1.4.1.10 For nonpotable water, submit the source and
reports confirming compliance with ASTM C1602/C1602M.
1.4.1.11 If FRS is specified, submit fiber material, length
or lengths, and fiber content.
1.4.1.12 Submit mill certificate showing conformance for
reinforcing steel or welded wire reinforcement.
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
1.4.1.13 When specified, provide test reports for shotcrete
boiled absorption and volume of permeable voids showing
compliance with the specified properties.
1.4.1.14 If hydration control admixtures are proposed by
the Contractor, the submittal shall be in accordance with
1.4.1.4 and the use of such admixture shall be assessed in
the prequalification test program in 1.5.1.
1.4.1.15 Submit repair procedure for shotcrete defects for
the Architect/Engineer’s acceptance. The submittal shall
include proposed materials, surface preparation, bonding
procedures, and final surface finish.
1.4.1.16 Submit curing materials and curing procedures
for shotcrete.
1.4.1.17 Submit name of proposed Contractor’s testing
agency and documentation of the agency’s certification to
ASTM C1077.
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1.5—Preconstruction testing by Contractor
1.5.1 Complete preconstruction testing required by
Contract Documents.
1.5.1.1 Testing of materials required as part of the preconstruction program shall be conducted by the Contractor’s
testing agency. Agency selection shall be acceptable to the
Architect/Engineer.
1.5.1.2 Notify the Architect/Engineer of the time and
place of preconstruction testing and provide Architect/Engineer with copies of testing reports.
1.5.1.3 Construct preconstruction test panels for examination by Architect/Engineer prior to project shotcrete placement. Preparation and testing shall comply with ASTM
C1140/C1140M. Mixture proportions shall meet the requirements of 2.5.
1.5.1.4 Construct test panels for each proposed shotcrete
mixture, each anticipated shooting orientation, and each
proposed nozzleman.
1.5.1.5 Testing required as part of the preconstruction
test program shall be provided by the Contractor’s testing
agency.
1.5.1.6 Test specimens cored or sawed from the panels
for compliance with the specified compressive strength in
accordance with ASTM C1604/C1604M and, when specified, flexural strength shall be in accordance with ASTM
C78/C78M with beams obtained by ASTM C42.
1.5.1.7 Complete testing to determine other specified shotcrete properties.
1.5.1.8 When FRS is specified, test flexural performance
using beams sawed from test panels for flexural strength in
accordance with ASTM C1609/C1609M and for residual
strength in accordance with ASTM C1609/C1609M or
C1399/C1399M. For toughness, test in accordance with
ASTM C1550.
1.5.1.9 When the degree of encasement of reinforcement
or severity of defects within the shotcrete sample is specified,
prepare additional panels with the specified reinforcement.
Core panels in accordance with ASTM C1140/C1140M.
Cores containing reinforcement shall be provided to the
Architect/Engineer for visual examination to determine
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acceptance. Cores for examination shall have a minimum
diameter of 3.75 in. and be the full thickness of the panel.
1.5.1.10 When the initial prequalification test panel is
rejected, a second panel may be shot and tested. If this panel
is acceptable, Work may proceed. If the second panel is not
acceptable, the Contractor shall change procedures, mixture
proportions, nozzlemen, or shotcrete equipment as necessary
before repeating the preconstruction testing. Do not proceed
with Work until preconstruction test results are satisfactory
to Architect/Engineer.
1.5.2 Preplacement verification
1.5.2.1 The forms shall be to line and grade and have
adequate support to remain rigid during shooting.
1.5.2.2 The formwork, substrata preparation, and cleanliness shall comply with Contract Documents.
1.5.2.3 The reinforcement type, size, grade, amount,
placement, cleanliness, and other requirements shall comply
with Contract Documents.
1.5.2.4 The placement of and clearance around reinforcement shall permit complete encasement of reinforcement
with shotcrete.
1.5.2.5 The mixture proportions shall be the same as the
approved submittal.
1.6—Testing during construction
1.6.1 Quality assurance by Owner or Architect/Engineer
1.6.1.1 The quality assurance testing agency shall be certified to ASTM C1077.
1.6.1.2 The Contractor shall provide the Owner and the
quality assurance testing agency with 2 working days’ notice
prior to the commencement of shotcreting.
1.6.1.3 The Owner’s quality assurance testing agency will
inspect, sample, and test materials and shotcrete production
as required by the Owner. When it appears that material
or workmanship fails to comply with the Contract Documents, the agency will immediately report deficiencies to
the Owner, Architect/Engineer, and Contractor.
1.6.2 Testing shotcrete
1.6.2.1 Test samples—Sample shotcrete in accordance
with ASTM C1385/C1385M. The Contractor is responsible
for the curing and protection of test panels on site prior to
the time that they are transported to the testing agency’s
laboratory.
1.6.2.2 Compressive strength samples—Obtain test specimens from job-site test panels unless Contract Documents
stipulate that in-place shotcrete test specimens are to be used.
1.6.2.3 Flexural strength or other flexural parameter
samples—For flexural strength, flexural parameter, or toughness requirements of FRS, only test panels shall be used.
1.6.2.4 Air content of mixture—When wet-mixture shotcrete is used and air entrainment is required, test for air
content at discharge from the truck chute in accordance with
ASTM C231/C231M prior to placement. Testing of dry-mix
shotcrete air content as shot is difficult and there is no plastic
state ASTM test method for this. Instead, it is recommended
to use hardened air voids tests by ASTM C457/C457M.
1.6.2.5 Temperature of shotcrete mixture—Determine the
temperature of the mixture using material sampled prior
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
1.7—Delivery, storage, and handling
Deliver, store, and handle materials to prevent contamination, segregation, corrosion, or damage. Store and protect
liquid admixtures as required to prevent evaporation and
freezing.
PART 2—PRODUCTS
2.1—Materials
2.1.1 Cement—Unless otherwise specified, cement shall
comply with ASTM C150/C150M.
2.1.2 Supplementary cementitious materials—When specified, supplementary cementitious materials shall comply
with ASTM C618 for fly ash and natural pozzolans, ASTM
C989/C989M-12a for slag cement, and ASTM C1240 for
silica fume.
2.1.3 Aggregate—Unless otherwise specified, aggregates
shall comply with ASTM C33/C33M for normalweight
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aggregates. The combined aggregate gradation shall comply
with grading No. 2 of ASTM C1436, unless otherwise
specified.
2.1.4 Water—Unless otherwise specified, water shall be
potable. When nonpotable water is permitted in Contract
Documents, water shall comply with ASTM C1602/
C1602M, except that wash water shall not be permitted
unless accepted by Architect/Engineer.
2.1.5 Admixtures—When admixtures are permitted or
required, the admixtures shall comply with ASTM C1141/
C1141M or, for hydration control admixtures, with ASTM
C494/C494M.
2.1.6 Fibers—When FRS is specified, fibers shall be the
types, material, and sizes required by Contract Documents.
Unless otherwise specified, they shall conform to ASTM
C1116/C1116M.
2.1.7 Reinforcement—Reinforcement shall be the grades,
types, and sizes required by the Contract Documents and,
unless otherwise specified, shall conform to one of the
following:
a) Deformed steel reinforcement: ASTM A615/A615M;
b) Welded wire reinforcement: ASTM A185/A185M;
c) Weldable reinforcement: ASTM A706/A706M.
2.1.8 Curing materials
2.1.8.1 Sheet materials—Unless otherwise specified,
sheet materials for curing shall comply with ASTM C171.
2.1.8.2 Curing compounds—Unless otherwise specified, curing compounds shall comply with ASTM C309 or
C1315. Volatile organic compounds (VOC) content shall
be in compliance with local air quality standards if those
requirements are more stringent.
2.1.8.3 Do not use curing materials that cause stains for
shotcrete having an architectural finish.
2.2—Packaged shotcrete materials
When permitted, packaged, preblended, dry combined
materials shall comply with ASTM C1480/C1480M.
2.3—Fiber-reinforced shotcrete
Unless otherwise specified, FRS shall comply with ASTM
C1116/C1116M.
2.4—Shotcrete properties
2.4.1 Shotcrete properties shall comply with the requirements of Contract Documents.
2.4.2 Where Contract Documents do not specify properties, the 28 day compressive strength shall be 4000 psi
minimum. The Compressive strength shall be assessed in
accordance with ACI 301.
2.4.3 Where Contract Documents specify FRS, the flexural strength shall be a minimum of 400 psi at 28 days.
2.4.4 Air content for shotcrete shall be within the limits
specified in the Contract Documents. Test frequency in
accordance with the Contract Documents.
2.4.5 Water-soluble chloride ion content in mixture—
Water-soluble chloride ion content shall not be greater than
that specified in Contract Documents.
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to discharge from the truck chute into the pump for wetmixture shotcrete or the shotcrete machine for dry-mix shotcrete. Testing shall be completed in accordance with ASTM
C1064/C1064M.
1.6.3 Test panels
1.6.3.1 Construct a test panel for each mixture, each
nozzleman, and each work day or for every 50 yd3 placed,
whichever results in the most panels. The face dimensions
of a test panel shall be a minimum of 16 x 16 in. with a
minimum depth of 5 in. For toughness testing in accordance
with ASTM C1550, the face dimension shall be 30.5 in. in
diameter and 3 in. thick. Shoot test panels in a vertical orientation only unless otherwise specified.
1.6.3.2 Condition test panels in accordance with ASTM
C1140/C1140M until transported to the testing agency’s
laboratory.
1.6.3.3 Obtain test specimens from test panels using
procedures outlined in ASTM C1140/C1140M or C1604/
C1604M. Cores shall be a nominal 3 in. diameter.
1.6.3.4 Test shotcrete specimens for compliance in accordance with ASTM C1604/C1604M for compressive strength.
1.6.3.5 When specified, test boiled absorption and volume
of permeable voids in accordance with ASTM C642.
1.6.3.6 When specified, test FRS specimens for flexural
parameters in accordance with 1.5.1.8.
1.6.4 Testing in-place shotcrete
1.6.4.1 Obtain core specimens from locations designated
by Architect/Engineer in accordance with ASTM C1140/
C1140M.
1.6.4.2 Unless otherwise specified, condition test specimens by soaking as specified in ASTM C1604/C1604M.
1.6.4.3 Test specimens in accordance with 1.6.2.
1.6.5 Testing shotcrete bond to substrate—If required by
Contract Documents, conduct bond testing of the shotcrete
to the substrate in accordance with ASTM C1583/C1583M.
1.6.6 Reporting of quality assurance test results—Provide
copies of any test results generated for quality assurance
to the Contractor, Owner, Architect/Engineer, and concrete
supplier.
5
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
2.4.6 Limitations on supplementary cementitious materials—Contract Documents shall specify limits, if any, on
type and quantity of supplementary cementitious materials
as defined in 2.1.2.
2.4.7 Shotcrete boiled absorption and volume of permeable voids—When required, conduct testing of shotcrete
absorption and volume of permeable voids in accordance
with ASTM C642. Specify acceptable limits in the Contract
Documents.
2.4.8 When required for FRS, flexural strength and flexural
parameters shall be in accordance with Contract Documents.
2.4.9 Bond strength—If required, specify the bond
strength. Testing for bond strength, when specified, shall be
on a minimum of three core samples and the strength shall
be the average of all samples.
2.5—Proportioning
Proportion shotcrete mixture by mass complying with
ASTM C94/C94M, or by volume complying with ASTM
C685/C685M, to satisfy the specified properties. For FRS,
proportion in compliance with ASTM C1116/C1116M.
2.6—Batching, mixing, and delivery
2.6.1 Batch, mix, and deliver wet-mixture shotcrete in
accordance with ASTM C94/C94M, C685/C685M, or
C1116/C1116M as applicable. For dry-mixture, batching,
mixing and delivering shall be in accordance with ASTM
C685 /C685M or C1116/C1116M.
2.6.2 Predampening or other methods suitable for prewetting the dry materials shall be used with packaged preblended
material for dry-mixture shotcrete.
PART 3—EXECUTION
3.1—Preparation of surface to receive shotcrete
3.1.1 Earth—Surfaces shall be prepared to line and grade.
Dampen surfaces immediately prior to shooting. No standing
water shall be visible.
3.1.2 Concrete, masonry, and shotcrete—Remove all
deteriorated, loose, unsound material or contaminants that
will inhibit bonding. Receiving surface shall be dampened
and allowed to dry to a saturated surface-dry (SSD) condition just prior to shotcrete application.
3.1.2.1 Chip surfaces to receive shotcrete to remove
offsets causing abrupt changes in thickness.
3.1.2.2 Roughen receiving surfaces that have been sawcut.
3.1.3 Rock—Remove loose material, mud, or other
foreign material that will inhibit bonding. Clean surface
prior to shotcrete placement. Dampen surface in accordance
with 3.1.1.
3.1.4 Reinforcement
3.1.4.1 Surface condition—The surface of the reinforcement shall be free of overspray or other deleterious materials
that inhibit development of bond with the shotcrete.
3.1.4.2 Reinforcement laps—Laps shall be noncontact and
shall be separated with a clearance of at least three times
the diameter of the largest reinforcing bar; three times the
maximum size aggregate; or 2 in., whichever is least, unless
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otherwise specified. Bars spliced by noncontact lap splices
in flexural members shall not be spaced transversely farther
apart than the smaller of 1/5 the required lap splice length
and 6 in. The use of contact lap splices necessary for support
of the reinforcing is permitted when approved by the Architect/Engineer. Lapped bars shall be in the same plane and
parallel to the direction of shooting. Welded splices are
permitted.
3.1.4.3 Secure reinforcement to prevent movement. The
use of mechanical splices is permitted when approved.
3.1.5 Forms—Use material of adequate thickness for
formwork to resist movement during shooting. Reinforce,
secure, and brace forms to minimize the effects of vibration
during shooting. Construct forms to allow escape of placement air, overspray, and rebound. Use form-release coating
material on removable forms unless the formed surface is to
subsequently receive an additional coating.
3.2—Joints
3.2.1 Construction joints—Taper construction joints at
approximately 45 degrees from receiving surface. Form
joints by cutting plastic shotcrete. Joints at slab intersections
shall be made at 90 degrees. Roughen shotcrete in the joint
face while it is still plastic.
3.2.2 Contraction joints—Where specified, place control
joints as indicated in Contract Documents. Discontinue reinforcement at control joints unless otherwise specified.
3.3—Alignment control
To establish thickness and plane of required surface, install
taut ground wires or other means to guide the nozzleman.
Install alignment control means at corners or offsets not
established by forms.
3.4—Application
3.4.1 Placement techniques
3.4.1.1 Use the same shotcrete mixture and equipment that
was used during nozzleman qualification and mixture design
acceptance for the production shotcrete.
3.4.1.2 Use temporary coverings to protect adjacent
surfaces from the deposit of overspray or impact from the
nozzle stream.
3.4.1.3 Install sufficient lighting and ventilation to provide
the shotcrete crew with a clear view of the shooting area.
Suspend Work and adopt corrective measures if visibility is
unsuitable for the application of quality shotcrete.
3.4.1.4 Provide a working surface that permits nozzlemen
unobstructed access to the receiving surface. Place shotcrete
first in corners, recesses, and other areas where rebound or
overspray cannot easily escape.
3.4.1.5 The supply of shotcrete material and air pressure at
the nozzle shall be uniform, providing a steady, continuous
flow of shotcrete with no detrimental surging or pulsing.
Maintain the velocity and consistency of shotcrete exiting
the nozzle at a uniform rate appropriate for the given job
conditions so that satisfactory material consolidation and
minimum rebound is achieved.
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
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3.4.1.6 Place shotcrete perpendicular to the receiving
surface with the nozzle held at such a distance to produce
maximum consolidation of the shotcrete and full encapsulation of the reinforcement.
3.4.1.7 Shoot dry-mixture shotcrete material within 45
min after batching or, in the case of prepackaged material,
within 45 min after predampening. Shoot wet-mixture shotcrete material within the time limits in ASTM C94/94M.
3.4.1.8 Apply shotcrete using a circular or elliptical motion
of the nozzle while building the required thickness.
3.4.1.9 Use sufficient material velocity, material consistency, and distance from the end of the nozzle to the receiving
surface to produce maximum consolidation of the shotcrete
and full encapsulation of the reinforcing steel.
3.4.1.10 In corners, direct the nozzle to bisect the corner
angle. Apply shotcrete so sagging or sloughing does not
occur. Where there is potential for accumulated rebound
or overspray material to be incorporated into the Work at
congested areas of steel reinforcement, embedded obstructions, corners, and recesses, use a compressed air blow pipe
to remove loose material from the Work.
3.4.1.11 Discontinue placement of shotcrete or shield the
nozzle stream if wind causes separation of ingredients in the
nozzle stream.
3.4.1.12 Do not reuse rebound or overspray in the Work.
3.4.1.13 Remove laitance from shotcrete surfaces that are
to receive additional shotcrete layers.
3.4.1.14 Surface preparation prior to the shooting of shotcrete shall comply with 3.1.5.
3.4.1.15 Do not apply shotcrete to surfaces with standing
or flowing water.
3.4.1.16 Remove hardened overspray and rebound from
adjacent surfaces, including exposed reinforcement.
3.4.2 Intermediate surfaces
3.4.2.1 When applying more than one layer of shotcrete,
use a cutting rod, brush with a stiff bristle, or other suitable
equipment to remove all loose material, overspray, laitance,
or other material that may compromise the bond of the
subsequent layer of shotcrete. Conduct removal immediately
after shotcrete reaches initial set.
3.4.2.2 Allow shotcrete to stiffen sufficiently before
applying subsequent layers. If shotcrete has hardened, clean
the surface of all loose material, laitance, overspray, or
other material that may compromise the bond of subsequent
layers. Bring the surface to a saturated surface-dry condition
at the time of application of the next layer of shotcrete.
3.4.3 Encasement of reinforcement
3.4.3.1 Place shotcrete to encase reinforcement and other
embedments, and provide the cover required by Contract
Documents.
3.4.3.2 Adjust air volume, material feed volume, and
distance of the nozzle from the Work as necessary to encase
reinforcement.
3.4.3.3 Keep the front face of the reinforcement clean
during shooting operations so that shotcrete builds up from
behind to encase the reinforcement without the formation of
shadows or voids.
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3.4.3.4 Shotcrete crew shall continuously remove accumulations of rebound and overspray using a compressed air
blowpipe, or other suitable device, in advance of deposition
of new shotcrete.
3.4.4 Hot weather shotcreting––Unless otherwise specified, do not place shotcrete when shotcrete temperature is
above 95°F, unless prequalification testing in 1.5.1 shows
that the required quality of materials can be achieved at
higher temperatures. The temperature of reinforcement and
receiving surfaces shall be below 90ºF prior to shotcrete
placement.
3.4.5 Cold weather shotcreting—Unless otherwise specified, shooting may proceed when ambient temperature is
40°F and rising. Stop shooting when ambient temperature
is 40°F and falling, unless measures are taken to protect the
shotcrete. Shotcrete material temperature, when shot, shall
not be less than 50ºF. Do not place shotcrete against frozen
surfaces.
3.4.6 Shotcrete temperature
3.4.6.1 Unless otherwise specified, when the average
of the highest and lowest ambient temperature during the
period from midnight to midnight is expected to drop below
40°F for more than 3 consecutive days, deliver shotcrete to
meet the following temperatures in place immediately after
placement:
a) Between 55°F and 75°F for sections less than 12 in. in
the least dimension;
b) Between 50°F and 70°F for sections to 36 in. in the
least dimension.
3.4.6.2 The minimum requirements of 3.4.6.1 may be
terminated when ambient temperatures greater than 50°F
occur during more than half of any 24-hour duration.
3.5—Finish
3.5.1 Gun finish—Leave finished shotcrete surface as gun
finish unless otherwise specified. Proceed to rod, rubber
float, wood float, or troweled finish.
3.5.2 Troweled or rod finish—Do not initiate cutting
or finishing until the shotcrete is sufficiently set to avoid
sloughing or sagging.
3.6—Curing
3.6.1 When the daily mean temperature is above 40°F,
curing shall be continuous for a minimum of 7 consecutive
days or for the time necessary to attain 70 percent of the
specified compressive or flexural strength, whichever period
is less.
3.6.2 If shotcrete is placed with daily mean temperatures
40°F or lower, cold weather protection shall be provided until
the shotcrete achieves 70 percent of the specified strength.
3.6.3 Unless otherwise specified, complete moist curing
by one of the following methods:
a) Ponding or continuous sprinkling for a minimum of 7
days;
b) Covering with an absorptive mat or sand that is kept
continuously wet;
c) Covering with impervious sheet material;
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
d) Use of curing compounds; apply twice the rate for
formed surfaces as recommended by manufacturer if the
surface is a gun finish.
3.6.4 Do not use natural curing in lieu of that specified in
this section unless the relative humidity of the air in contact
with the shotcrete remains at or above 85 percent and such
curing is authorized by Architect/Engineer.
3.7—Protection
3.7.1 After placement
3.7.1.1 Unless otherwise specified, immediately after
placement, protect shotcrete from premature drying or
excessively hot or cold temperatures and mechanical injury.
3.7.1.2 Maintain shotcrete protection to prevent freezing
of the shotcrete and to ensure the necessary strength development for structural safety. Remove protection in such a
manner that the maximum decrease in temperature measured
at the surface of the shotcrete in a 24-hour period shall not
exceed the following:
a) 50°F for sections less than 12 in. in the least dimension;
b) 40°F for sections from 12 to 36 in. in the least dimension.
3.7.2 Protect surfaces not intended for shotcrete placement against deposit of rebound and overspray or impact
from nozzle stream.
3.8—Tolerances
3.8.1 Dimensional tolerances of shotcrete shall comply
with Contract Documents.
3.9—Repair of shotcrete
3.9.1 General
3.9.1 Repair defects in shotcrete in accordance with an
approved procedure submitted in 1.4.1.15.
3.9.1.2 Remove voids, shadows, sagging, or other defects
in the hardened shotcrete using light-duty chipping hammers
(maximum 18 lb) followed by high-pressure water blasting
or grit blasting to remove bruised shotcrete surface.
3.9.1.3 Conduct removal of defective shotcrete without
the creation of feather edges.
3.9.1.4 In the repair of core hole surfaces and sawcut
edges, roughen the core hole or cut surface and predampen
prior to repair.
3.9.2 Shotcrete repair with commercial patching products—Repair shotcrete with commercial patching products,
including:
a) Portland cement mortar, modified with a latex bonding
agent conforming to ASTM C1059/C1059M, Type II;
b) Packaged, dry concrete repair materials conforming to
ASTM C928/C928M.
3.9.3 Removal of stains, rust, efflorescence, and surface
deposits—Remove stains, rust, efflorescence, and surface
deposits considered objectionable by Architect/Engineer by
methods acceptable to the Architect/Engineer.
3.10—Acceptance of Work
3.10.1 Remove and replace shotcrete that exhibits laminations, voids, or sand pockets exceeding the specified quality.
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Remove and replace shotcrete that does not comply with the
Contract Documents.
3.10.2 Shotcrete Work that meets specifications shall be
accepted.
3.10.3 Shotcrete Work that has previously failed to meet
one or more requirements, but has been repaired to bring it
into compliance shall be accepted.
3.10.4 Shotcrete Work that fails to meet one or more
requirements and that cannot be brought into compliance
shall be either accepted or rejected by Architect/Engineer.
Modifications to the mixture proportions or the shotcreting
procedures shall be implemented to assure that remaining
Work complies with the requirements.
3.10.5 The basis for acceptance or rejection of shotcrete
properties shall be the specified compressive or flexural
strength. When additional criteria, properties, or both are
required in the Contract Documents, acceptance criteria
shall include compliance with those requirements.
3.10.6 Compliance with test properties
3.10.6.1 Compressive strength—Consider the compressive strength adequate if the average of the three cores from
a test panel or from in-place shotcrete exceeds 85 percent of
the specified compressive strength and no single core is less
than 75 percent of the specified compressive strength.
3.10.6.2 Flexural strength—When required, the average
flexural strength of a set of three test beams from one panel
shall equal or exceed the specified flexural strength.
3.10.6.3 Boiled absorption and volume of permeable
voids—When required, the average of tests on three specimens from a test panel, or from in-place shotcrete, shall
be less than or equal to the specified boiled absorption and
specified volume of permeable void limits at the specified
test age with no single test greater than the specified boiled
absorption plus 1 percent.
3.10.6.4 Flexural parameters—For FRS, and when
required, flexural parameters and toughness requirements
shall comply with specified requirements in the Contract
Documents.
3.10.6.5 Bond—When required, the average of the bond
strength of the specified number of cores shall exceed the
specified minimum strength with no single core bond
strength less than 75 percent of the specified strength.
(nonmandatory portion follows)
NOTES TO SPECIFIER
General notes
G1. ACI Specification 506.2 is to be used by reference or
incorporation in its entirety in the Project Specification. Do
not copy individual sections, parts, articles, or paragraphs
into the Project Specification, because taking them out of
context may change their meaning.
G2. If Sections or Parts of ACI Specification 506.2 are
copied into the Project Specification or any other document,
do not refer to them as an ACI Specification because the
specification has been altered.
G3. A statement such as the following will serve to make
ACI Specification 506.2 a part of the Project Specification:
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
“Work on (Project Title) shall conform to all requirements
of ACI 506.2 (Specification number with date suffix and
title) published by the American Concrete Institute, Farmington Hills, Michigan, except as modified by these Contract
Documents.”
G4. Each technical Section of ACI Specification 506.2 is
written in the three-part section format of the Construction
Specifications Institute, as adapted for ACI requirements.
The language is imperative and terse.
G5. ACI Specification 506.2 is written to the Contractor.
When a provision of this specification requires action by
the Contractor, the verb “shall” is used. If the Contractor
is allowed to exercise an option when limited alternatives
are available, the phrasing “either...or...” is used. Statements
provided in the specification as information to the Contractor
use the verbs “may” or “will.” Informational statements
typically identify activities or options that, “will be taken”
or “may be taken” by the Owner or Architect/Engineer.
FOREWORD TO CHECKLISTS
F1. This foreword is included for explanatory purposes
only; it is not a part of ACI Specification 506.2.
F2. ACI Specification 506.2 may be referenced by the
specifier in the Project Specification for any building project,
together with supplementary requirements for the specific
project. Responsibilities for project participants must be
defined in the Project Specification. ACI Specification 506.2
9
cannot and does not address responsibilities for any project
participant other than the Contractor.
F3. Checklists do not form a part of ACI Specification
506.2. Checklists assist the specifier in selecting and specifying project requirements in the Project Specification.
F4. The Mandatory Requirements Checklist indicates
Work requirements regarding specific qualities, procedures,
materials, and performance criteria that are not defined in
ACI Specification 506.2. The specifier must include these
requirements in the Project Specification.
F5. The Optional Requirements Checklist identifies specifier choices and alternatives. The checklist identifies the
sections, parts, and articles of the ACI Reference Specification 506.2 and the action required or available to the specifier. The specifier should review each of the items in the
checklist and make adjustments to the needs of a particular
project by including those selected alternatives as mandatory requirements in the Project Specification.
F6. The Submittals Checklist identifies information or
data to be provided by the Contractor before, during, or after
construction.
F7. Recommended references—Documents and publications that are referenced in the checklists of ACI Specification 506.2 are listed below. These references provide guidance to the Specifier and are not considered to be part of ACI
Specification 506.2.
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10
SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
MANDATORY REQUIREMENTS CHECKLIST
Section/Part/Article
1.1.1
Notes to Specifier
Specify whether shotcrete is structural or nonstructural. Specify if fiber-reinforced shotcrete (FRS) or other specialty
shotcrete is required.
1.4.1.9
Specify if ACI Nozzleman Certification is required for nonstructural shotcrete.
1.5.1
Specify if preconstruction testing is required.
1.6.3.1
Specify panel orientation to match Work if other than vertical.
2.1.7
Specify the grades, types, and sizes of reinforcement required.
2.4.1
Specify compressive strength required. For FRS, specify the flexural strength and other flexural parameters.
2.4.2
2.4.4
2.4.5
Specify maximum w/cm based on project service conditions. Refer to ACI 318 or 350 to determine project requirements. Guidance with regard to freezing and thawing can be obtained from ASTM C33/C33M.
Air entrainment may be required where the shotcrete is exposed to freeze/thaw, seawater, or deicing salts. Specify
minimum air void parameters based on project service conditions. Refer to ACI 318 or 350 to determine project
requirements. Guidance on the need for air entrainment to protect against freezing and thawing can be found in
ASTM C33/C33M. Also specify the frequency of air testing.
Specify maximum water-soluble chloride ion content based on project service conditions. Refer to ACI 318 or 350
to determine project requirements.
2.4.6
Specify limits, if any, on the types and dosages of supplementary cementing material.
2.4.7
If required, specify limits on the voids and absorption properties.
2.4.8
Specify if FRS is required and, if so, the flexural strength and flexural parameters required.
2.4.9
If required, specify bond strength of shotcrete to substrata.
2.5
3.4.3
Specify when mass or volume proportioning of the shotcrete is required. Shotcrete mixtures are normally proportioned to achieve a specified compressive strength. Refer to ACI 506R if specific properties other than strength are
required.
Specify reinforcement cover requirements for shotcrete based on project service conditions. Refer to ACI 318 or 350
to determine project requirements.
3.4.5
Specify cold weather procedures. Refer to ACI 306R and 306.1.
3.8.1
Specify tolerances based on function and appearance. Shotcrete can be built to the same tolerance as cast-in-place
concrete; however, for some structures such as tunnels, only cover thickness is required and tolerances are not specified unless project-specific requirements dictate. Sometimes shotcrete tolerances are increased by a factor of 2 from
those in ACI 117. Refer to ACI 318 or 350 to determine project requirements.
OPTIONAL REQUIREMENTS CHECKLIST
Section/Part/Article
1.4.1.7
1.4.1.13
Notes to Specifier
Specify when there will be other submittal requirements. Some submittals may not be needed for some projects.
Specify when aggregate absorption testing is required. The absorption values may be used to correct for absorbed
moisture in the calculation of w/cm.
Specify acceptance values for boiled absorption and volume of permeable voids. Typical values for quality shotcrete
are a Maximum of 8 percent boiled absorption and 15 percent volume of permeable voids.
1.5.1.5
Specify when testing for other shotcrete properties will be required.
1.5.1.6 and 1.5.1.8
Specify when flexural strength testing is required. Specify when a ratio of compressive to flexural strength should
be established so that during construction the more economical compressive strength testing might augment quality
control requirements.
1.5.1.9
Specify acceptance criteria for degree of reinforcement encasement or severity of defects.
1.6.2.2
Specify when test specimens from other than test panels, such as from in-place shotcrete, are required.
1.6.2.4 and 2.4.4
Specify air content for wet-mixture shotcrete, if required.
1.6.3.1
Specify test panel orientation if other than vertical.
1.6.3.2
1.6.3.6
Specify when samples should be conditioned by a procedure other than soaking in accordance with ASTM C1604/
C1604M.
When flexural strength or toughness testing is required, specify where and how samples are to be taken. Refer to
ACI 506R.
1.6.5 and 2.4.9
Specify when bond tests are required and specify where bond tests are to be conducted.
2.1.1
Specify when a specific type of cement is required to satisfy project requirements such as durability. Refer to ACI
318 or 350 to determine project requirements.
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1.4.1
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SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
11
2.1.2
Specify when supplementary cementitious materials are required or permitted to satisfy project requirements. Refer
to ACI 318 or 350 to determine project requirements.
2.1.3
Specify when an alternative aggregate will be acceptable or is required.
2.1.4
2.1.5
Specify when nonpotable water will be acceptable, including any specific limitations. Refer to ACI 318 or 350 to
determine project requirements. ASTM C1602/C1602M provides testing requirements for nonpotable water.
Specify when ready-mixed wash water will be acceptable and include any limitations.
Specify when admixtures are permitted or required, including type and grades. Refer to ACI 318 or 350 to determine
project requirements. ASTM C1141 Type 1, Grade 3, and Type 2, Grade 3, are supplemental cementitious materials
and are not admixtures.
Shotcrete placement reduces entrained air content such that shotcrete with a 7 percent or higher air content prior to
shooting will have an entrained air content of approximately 3 to 4 percent after placement.
Wet-mixture shotcrete exposed to moderate or severe freezing-and-thawing conditions should have an entrained air
content of at least 6 to 7 percent prior to shooting. Obtaining greater than 4 percent air in the in-place material is
difficult.
Specifying air entrainment for dry-mixture shotcrete is not common but has been satisfactorily used in severe
freezing-and-thawing exposures.
Specify limits and types of other acceptable admixtures. Specify maximum dosage if important.
Calcium chloride accelerators are not recommended for reinforced shotcrete structures. Refer to tables in ACI
201.2R and 318 or 350 for limits. If specified, calcium chloride should conform to ASTM D98.
2.1.6
Specify what types of fibers are required. Refer to ACI 506.1R and ACI 506.5R
2.1.7
Specify when there are limitations on what reinforcement is required or permitted. Refer to ACI 318, 301, or 350 to
determine project requirements.
2.1.8.1
Specify when sheet materials for curing are not permitted. Refer to ACI 318 or 350 to determine project requirements.
2.2
Specify when packaged preblended materials are permitted, including any limitations.
2.3
Specify when there are additional limitations and requirements for FRS.
2.4.3
Specify flexural strength and other flexural parameters when required on the project. Specify the limits. Refer to ACI
506.1R and ACI 506.5R.
2.4.4
If it is desired to confirm the air void parameters in hardened shotcrete, use the procedures in ASTM C457/C457M.
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2.4.6
2.4.7
Specify limitations on suitability of supplementary cementitious materials, when they are permitted. Refer to ACI
318 or 350 to determine project requirements.
Specify when shotcrete boiled absorption and volume of permeable voids testing will be required. Specify the
requirements. Guidance can be found in ACI 506R.
2.4.9
Specify bond strength if required.
3.1.4.2
Specify when reduction of clearances between reinforcing bar laps may be permitted based on preconstruction
testing.
3.1.5
Specify when air-supported forms may be used.
3.2.2
Specify when contraction joints are required. Also specify if reinforcement is to pass through the joint.
3.4.4
3.4.5
Specify when a shotcrete temperature limit that is higher or lower than 95°F for shotcrete members is required or
acceptable based on the member being shot, location, relative humidity, and past experience. Review ACI 305R for
guidance on specifying a higher or lower temperature.
If shotcrete delivered in hot weather with a temperature higher than 95°F has been used successfully in given
climates or situations, the higher temperature may be specified in place of the 95°F limit.
Specify when revised temperature requirements may be acceptable. Requirements herein have been taken from ACI
306.1. For projects in cold climates, such as in northern winters, or in situations where it is prudent to require the
Contractor to follow specific procedures to achieve the limits of 3.4.6, the temperature limits for cold weather may
be deleted and ACI 306.1 can be referred to in its entirety. Options within ACI 306.1 must then be exercised.
3.4.6.1
Specify when other ambient temperatures are permitted.
3.5
Specify if a finish other than gun finish is required.
3.6.3
Specify alternative curing systems if permitted.
3.7.1
Requirements for rate of temperature change have been excerpted from ACI 306.1. For optional cold-weather shotcreting requirements, specify ACI 306.1 in its entirety, if appropriate.
3.9
Specify what repair procedures are acceptable or required.
3.9.1
Edges of the repair area should not be feather-edged. Common methods used for edge preparation include sawcutting, chipping, grinding, sandblasting, hydro-milling, or other means to a depth of 1/2 to 1 in. normal to the
surface of the member. Note: if saw-cutting or grinding is used, care should be taken to ensure reinforcing steel is
not cut or damaged.
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12
SPECIFICATION FOR SHOTCRETE (ACI 506.2-13)
SUBMITTALS CHECKLIST
Section/Part/Article
1.4.1.1
Notes to Specifier
Mixture proportions for each mixture design and test reports for hardened and plastic properties for each mixture
design.
1.4.1.2
Test reports of compressive strength and, when FRS is specified, flexural strength and flexural parameters.
1.4.1.3
w/cm for wet-mixture only.
1.4.1.4
Admixture data.
1.4.1.5
Cementitious materials data.
1.4.1.6
Aggregate data.
1.4.1.7
When required, aggregate absorption.
1.4.1.8
Qualifications, certification, and experience of Work crew. Nozzlemen certification.
1.4.1.9
Submit proof of shotcreting experience.
1.4.1.10
Water source and data. Water report, when required.
1.4.1.11
When specified, fiber material, length, and fiber content.
1.4.1.12
Certificate showing compliance of reinforcement to specifications.
1.4.1.13
When specified, shotcrete boiled absorption and volume of permeable voids test reports.
1.4.1.14
For hydration control admixtures, submit data.
1.4.1.15 and 3.9.1
When necessary, proposed repair procedures.
1.4.1.16
Data showing that curing materials comply with specifications.
1.4.1.17
Contractor’s testing agency.
3.7.1
Method of measuring concrete surface temperature.
CHECKLIST REFERENCES
ACI committee documents and documents published by
other organizations are listed first by document number and
year of publication.
ACI 506R-05—Guide to Shotcrete
ACI 506.1R-08—Guide to Fiber-Reinforced Shotcrete
ACI 506.5R-09—Guide for Specifying Underground
Shotcrete
American Concrete Institute (ACI)
ACI 117-10—Specification for Tolerances for Concrete
Construction and Materials and Commentary
ACI 201.2R-08—Guide to Durable Concrete
ACI 301-10—Specifications for Structural Concrete
ACI 305R-10—Guide to Hot Weather Concreting
ACI 306R-10—Guide to Cold Weather Concreting
ACI 306.1-90—Standard Specification for Cold Weather
Concreting (Reapproved 2002)
ACI 318-11—Building Code Requirements for Structural
Concrete and Commentary
ACI 350-06—Code Requirements for Environmental
Engineering Concrete Structures
ASTM International
ASTM C33/C33M-13—Standard Specification for
Concrete Aggregates
ASTM C1141/C1141M-08—Standard Specification for
Admixtures for Shotcrete
ASTM C1602/C1602M-12—Standard Specification for
Mixing Water Used in the Production of Hydraulic Cement
Concrete
ASTM C1604/C1604M-05 (2012)—Standard Test
Method for Obtaining and Testing Drilled Cores of Shotcrete
ASTM D98-05—Standard Specification for Calcium
Chloride
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American Concrete Institute®
Advancing concrete knowledge
As ACI begins its second century of advancing concrete knowledge, its original chartered purpose
remains “to provide a comradeship in finding the best ways to do concrete work of all kinds and in
spreading knowledge.” In keeping with this purpose, ACI supports the following activities:
· Technical committees that produce consensus reports, guides, specifications, and codes.
· Spring and fall conventions to facilitate the work of its committees.
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Benefits of membership include a subscription to Concrete International and to an ACI Journal. ACI
members receive discounts of up to 40% on all ACI products and services, including documents, seminars
and convention registration fees.
As a member of ACI, you join thousands of practitioners and professionals worldwide who share a
commitment to maintain the highest industry standards for concrete technology, construction, and
practices. In addition, ACI chapters provide opportunities for interaction of professionals and practitioners
at a local level.
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Phone:
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Specification for Shotcrete
The AMERICAN CONCRETE INSTITUTE
was founded in 1904 as a nonprofit membership organization dedicated to public
service and representing the user interest in the field of concrete. ACI gathers
and distributes information on the improvement of design, construction and
maintenance of concrete products and structures. The work of ACI is conducted by
individual ACI members and through volunteer committees composed of both members
and non-members.
The committees, as well as ACI as a whole, operate under a consensus format,
which assures all participants the right to have their views considered. Committee
activities include the development of building codes and specifications; analysis of
research and development results; presentation of construction and repair
techniques; and education.
Individuals interested in the activities of ACI are encouraged to become a member.
There are no educational or employment requirements. ACI’s membership is
composed of engineers, architects, scientists, contractors, educators, and
representatives from a variety of companies and organizations.
Members are encouraged to participate in committee activities that relate to their
specific areas of interest. For more information, contact ACI.
www.concrete.org
American Concrete Institute®
Advancing concrete knowledge
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