Background
and
Discussion
PCI DESIGN HANDBOOK
PRECAST AND PRESTRESSED
CONCRETE
7th Edition
PCI Industry Handbook
Committee
Prepared by
PCI Industry Handbook Committee
Greg Force, P.E., FPCI, Chairman
Neal S. Anderson, P.E., S.E., FPCI, FACI
Ned M. Cleland, PhD, P.E., FPCI, FACI
Harry A. Gleich, P.E., FPCI, FACI
Gary A. Householder,
Househol der, P.E.
P.E.
Pat Hynes, P.E., FPCI
Phillip J. Iverson, P.E.
Walter Korkosz, P.E., S.E.
Jason Krohn, P.E.
P.E.
Karen Laptas, P.E.
David J. Larsen, P.E., S.E
Jason P. Lien, P.E.
Rafael A. Magana,
M agana, P.E.
Michael I. Owings, P.E., S.E.
Stephen Pessiki, PhD, FPCI, FACI
Steven H. Peterson, P.E.
Courtney B. Phillips, P.E., S.E.
Timothy R. Salmons, P.E., S.E.
Kim E. Seeber, P.E.,
P.E., FPCI
Larbi Sennour, PhD, P.E.,
P.E., FPCI,
FPCI , FACI
a
Fattah Shaikh , PhD, P.E., FPCI
Irwin J. Speyer, P.E.,
P.E., FPCI,
FPCI , FACI
Peter G. Troiani,
Troiani, P.E., S.E.
Helmuth Wilden, P.E., FPCI
Charles E. Wynings, P.E.
P.E.
a. Deceased January 10, 2008
Consulting Members
Robert F. Mast, P.E.,
P.E., S.E., FPCI,
FP CI, HACI
Jagdish C. Nijhawan, P.E., FPCI
J. Robert Norris, P.E.
Foreword
The Precast/Prestressed Concrete Institute (PCI) updates
and publishes the PCI Design Handbook: Precast and
Prestressed Concrete1 in cycles coincident with publication o the American Concrete Institute’s (ACI’s)
(ACI’s) Building
Code Requirements or Structural Concrete (ACI 318-05)
and Commentary (ACI 318R-05) .2 The seventh edition o
the PCI Design Handbook , published in 2010, continues
that tradition. Each update o the PCI Design Handbook
reects the modifcations adopted by ACI 318 as well
as the most recent research and experience o designers
regularly engaged in the design o precast and prestressed
concrete structures.
Introduction
The publication o the seventh edition o the PCI Design
Handbook continues to meet the goals set orth by the Precast/Prestressed Concrete Institute, which was established
in 1954 as the Prestressed Concrete Institute. The current
name was adopted in 1989 to better reect the interests o
both prestressed concrete producers and those that manuacture nonprestressed precast concrete components. The
goal is to advance the design, manuacture, and use o
precast and prestressed concrete.
The seventh-edition PCI Design Handbook ’s primary
objective remains the same as it was with the frst edition,
published in 1971; that is, “… to make it easier or architects and engineers to use prestressed and precast concrete.
It is intended to be a working tool, assisting the designer in
achieving optimum solutions in minimum time.”
Editor
Helmuth Wilden, P.E., FPCI
The seventh edition o the PCI Design Handbook background and discussion paper is the sixth document o i ts
type. The frst was published or the second-edition PCI
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129
Design Handbook and was an authored paper titled “Background and Discussion on PCI Design Handbook , Second
Edition.” It was published in the January–February 1980
issue o the PCI Journal. Subsequent papers with the same
intent and similar titles were published as ollows:
•
•
•
For the third-edition PCI Design Handbook : May–
June 1988, PCI Journal
For the ourth-edition PCI Design Handbook : November–December 1996, PCI Journal
•
•
For the fth-edition PCI Design Handbook : July–August 1998, PCI Journal
•
•
For the sixth-edition PCI Design Handbook : March–
April 2006, PCI Journal
•
Purpose
The main purpose o the background and discussion o the
seventh edition o the PCI Design Handbook is to identiy
signifcant changes rom the sixth edit ion on a chapter-bychapter basis and explain the rationale or these changes.
Other purposes are to describe current work in progress
toward the eighth edition o the PCI Design Handbook and
to establish goals or uture work.
Synopsis of changes
from the sixth-edition
PCI Design Handbook
Table 1 outlines the dierences rom the sixth edition to
the seventh edition o the PCI Design Handbook .
The seventh edition o the PCI Design Handbook , while
similar to the sixth edition in many ways, incorporates
modifcations that generally all into one o the ollowing
categories:
•
130
It includes updated inormation reecting changes
rom ACI 318-02 to ACI 318-05, incorporating new
and revised provisions. Note that changes related to
ACI 318-08 are identifed in the appendix to the seventh edition.
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It includes updated inormation based on current standard practices o the industry.
It includes updated inormation based on results o
recent research in the industry.
It expands text o selected topics t o provide morecomprehensive discussion.
Selected text, fgures, tables, Design Aids, and examples are rewritten, modifed, and edited or improved
clarity.
The user o the PCI Design Handbook will observe several
somewhat subtle dierences rom the sixth edition:
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•
•
Some things in the seventh-edition PCI Design Handbook
remain unchanged rom the sixth edition. The number o
chapters has been increased rom 11 to 15 as a result o
the PCI Industry Handbook Committee’s intent to provide
more emphasis on some topics, including fre endurance and
vibrations. Chapter 9, Precast and Prestressed Concrete: Materials, is totally new and compiles discussions o materials
that were in individual chapters in previous editions. Chapter
2 is also totally new and includes the notation used throughout the entire handbook on a chapter-by-chapter basis.
It incorporates comments by the sixth-edition PCI
Design Handbook Blue Ribbon Review Committee
that could not be included in the sixth edition.
•
•
It includes the correction o errors in the sixth edition
that were published as errata in the May–June 2007
issue o the PCI Journal.
•
•
•
•
Equations are numbered consecutively in e ach chapter.
For example, Eq. 6.5.2.1 in the sixth edit ion is now
Eq. (6-2) and Eq. 6.12.1.1 is now Eq. (6-93).
A complete list o design examples is included at the
end o the oreword to the handbook.
Previous charts shown as fgures are now Design Aids,
and a complete list is included at the end o the oreword to the handbook.
All fgures and tables are identifed with a three-digit
number. For example, Table 6.6.5.2 in the sixth edition
is now Table 6.6.3 and Fig. 6.7.3.1 is now Fig. 6.7.1.
The frst digit reers to the chapter, the second digit
reers to the main section in which the fgure or table
appears, and the third digit represents the consecutive
order in the main section.
Chapters are identifed on each page with a tab box at
the edge o the page or easy reerence.
The term member, representing a precast concrete
unit, has been changed to component throughout the
handbook. This was done to be consistent with the
title or chapter 5 o the seventh-edition PCI Design
Handbook.
For the most part, American Concrete Institute nomenclature and ormatting has been used.
The user will also observe that some sections o the sixth edition have been omitted rom the seventh edition. They are:
Table 1. Comparison o 6th and 7th editions o the PCI Design Handbook
Sixth edition
Chapter
Pages
Figures
1
32
58
Design
Aids
Pages
Figures
Tables
Design
examples
Design
Aids
5
n.a.
n.a.
28
63
n.a.
n.a.
n.a.
New
n.a.
n.a.
n.a.
n.a.
n.a.
18
n.a.
n.a.
n.a.
n.a.
3
Ch. 2 in
6th
58
8
32
n.a.
8
64
8
32
n.a.
11
4
Ch. 3 in
6th
124
20
2
19
26
98
34
4
13
26
5
Ch. 4 in
6th
132
25
8
43
14
152
38
8
48
15
6
102
39
5
23
15
116
39
11
26
14
7
22
15
3
n.a.
n.a.
36
18
4
3
n.a.
8
Ch. 5 in
6th
36
27
4
6
n.a.
28
27
4
4
n.a.
9
New
n.a.
n.a.
n.a.
n.a.
n.a.
42
22
10
n.a.
n.a.
10
Sect. 9.3
in 6th
26
19
13
5
n.a.
26
17
13
4
n.a.
11
Sects.
9.1 and
9.2 in 6th
23
4
15
4
n.a.
26
4
15
4
n.a.
12
Sect. 9.7
in 6th
8
2
3
3
n.a.
10
2
3
3
n.a.
13
Ch. 8 in
6th
34
6
13
2
n.a.
34
6
11
2
n.a.
14
Ch. 10 in
6th
36
n.a.
n.a.
n.a.
n.a.
36
n.a.
n.a.
n.a.
n.a.
15
Ch. 11 in
6th
58
n.a.
n.a.
n.a.
31
62
n.a.
n.a.
n.a.
37
New
n.a.
n.a.
n.a.
n.a.
n.a.
22
6
8
n.a.
n.a.
691
223
103
105
94
776
278
115
107
103
Totals
•
Design
examples
Tables
2
Appendix
•
Seventh edition
Section 9.5, Quality Assurance and Control. The committee elt that this section was redundant because
three major PCI quality-control manuals already exist.
They are MNL-116 3 or structural precast concrete,
MNL-1174 or architectural precast concrete, and
MNL-1305 or glass-fber-reinorced concrete.
Section 9.9, Precast Segmental Construction. This topic is outside the area o building construction, which
is the emphasis o the handbook, and more up-to-date
inormation is available in other publications.
•
Section 9.10, Coordination with Mechanical, Electrical and Other Sub-Systems. At the time o publicati on
o the seventh edition, it was the i ntent o PCI to develop a recommended practice and guidelines or tota l
precast concrete structures and the committee considered that this new publication would provide more
inormation than could be included in the handbook.
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The handbook committee
process
It is o interest to review the process by which the seventh
edition o the PCI Design Handbook was created. As soon
as the sixth edition was published in 2004, a new Industry
Handbook Committee was established. It consisted o 25
ull members and 3 consulting members. Eighteen o these
people served on the previous sixth-edition committee.
They represent various interests within the industry and
include 15 specialty engineers, 9 plant engineers, 2 tradeassociation engineers, and 2 academics.
The process used was as ollows:
1.
2.
The committee agreed on a new arrangement, increasing the number o chapters rom 11 to 15, as described
later in this article.
3.
A subgroup o three to seven members (including a
chairperson) was established or each chapter. The
objective o each chapter subgroup was to perorm a
detailed review o the existing chapter and an exhaustive review o research and publications rel evant to the
subject o the chapter subsequent to the sixth edition.
4.
5.
6.
132
The committee used the sixth edition as the baseline,
with the understanding that ACI 318-05, American
Society o Civil Engineers (ASCE) 7-05, 6 and International Building Code 2006 (IBC 2006)7 would be the
relevant reerences or the seventh edition.
Ater analysis o inormation discovered in the subgroups’ reviews and discussion regarding i mproved
and/or updated content, each subgroup developed a
drat o its respective chapter.
Each chapter was then edited by the editor, and a
committee-ballot version was created.
Each chapter was balloted by the committee, and all
comments were resolved during meetings o the ull
committee. This process included 14 ace-to-ace
meetings and 9 web-based teleconerences over the
our-year course o development. The intensity peaked
during 2009 with two ace-to-ace meetings and all
nine o the teleconerences. In addition, hundreds o
individual telephone calls and thousands o emails between members and to and rom the editor took place.
7.
Additional editing was done, and a Technical Activities Council (TAC) ballot version was created.
8.
Each chapter was balloted by TAC with resolution o
all comments by both TAC and the Industry Handbook
Committee.
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9.
Based on these approved versions, a blue-ribbon-review
version was created. This fnal review phase consisted o
the Blue Ribbon Review Committee, made up o plant
engineers, specialty engineers, consulting engineers,
academics, and associate members. Each member o the
Blue Ribbon Review Committee is a recognized leader
in the analysis and design o precast and prestressed
concrete structures or an expert in a closely related feld.
The members o the Blue Ribbon Review Committee are
noted in the oreword to the handbook. Ater a six-week
review period, this group met or three days and oered
valuable comments that were considered by the Industry
Handbook Committee. Most were accepted as improving
the publication. Others will be considered as new business or the eighth edition.
10. A fnal version o each chapter was then created and
reviewed thoroughly by the original chapter subgroup.
This review resulted in a ew corrections and urther
improvement.
11. In addition, a comprehensive editorial and technical
review o the handbook was carried out by the PCI
Publications Department, led by Emily Lorenz, editorin-chie o the PCI Journal, as well as Jason Krohn,
PCI’s Managing Director o Technical Activities.
It is commendable that the seventh edition o the PCI
Design Handbook was created primarily through the
volunteer eorts o the committee members and many others. Thousands o hours were devoted to its development,
which, at normal consulting rates, would easily exceed a
value o $2 million.
The ollowing presents a chapter-by-chapter review o
the contents, outlining the general content and emphasizing changes rom the sixth edition as well as the rationale
behind these changes.
Chapter 1—Precast and
Prestressed Concrete:
Applications
This chapter is intended to provide the user o the handbook with a general understanding o the many applications o precast and prestressed concrete used in buildings
and other structures. (For bridges, a separate publicat ion
by PCI, the Precast Prestressed Concrete Bridge Design
Manual,8 should be consulted.)
As is typical with each new edition o the PCI Design Handbook, the photographs have been updated to illustrate the
current state o the art. As a result o the newer photographs,
captions and text reerring to the photographs have been
updated. Although the handbook is not intended or bridges,
a photograph o the Walnut Lane Memorial Bridge ( Fig.
1) has been retained to remind the user o the beginning o
the prestressed concrete industry in the United States. For
additional inormation related to the history o the industry,
reer to Reections on the Beginnings o Prestressed Concrete in America,9 published in 1981, and PCI Visions Taking
Shape,10 published in 2004. These documents commemorate
the 25th and 50th anniversaries o PCI, respectively.
The sixth-edition fgure o typical products has been replaced with a collage o photographs to better illustrate the
variety o products available ( Fig. 2).
Because o the growing emphasis on sustainability, section
1.1.3, “Sustainability and LEED Considerations,” has been
added to describe the benefts o precast and prestressed
concrete in achieving long-lasting and energy-efcient
structures.
A new section 1.2.1.7, Educational Facilities, has been
added to better illustrate the importance o these applications and to present to the user o the handbook the superior solutions that precast and prestressed concrete oers to
the owners o these acilities.
Figure 1. Walnut Lane Memorial Bridge.
stairs, and section 3.3.12 and Design Aid 3.12.11, which
provides guidelines for stadium riser sections. Design Aid
3.12.7 has been added to assist in preliminary sizing of
non-load-bearing wall panels.
The sixth-edition section 1.3, Materials, was completely
removed rom chapter 1. It was extensively expanded and
has become the new chapter 9 o the PCI Design Handbook, seventh edition. See the discussion in this article on
chapter 9 or urther details o the changes and additions on
the subject o materials.
Chapter 4—Analysis
and Design of Precast/
Prestressed Concrete
Structures
Chapter 2—Notations
The chapter on the analysis and design o precast and prestressed concrete structural systems has been updated to reect the requirements o ACI 318-05, IBC 2006, and ASCE
7-05. There has been an update o the discussion on precast
concrete lateral systems, which reects the more-severe
treatment in ASCE 7-05 o cantilevered column systems.
This chapter is completely new and includes the notations
or the entire handbook. This is the result o the PCI Industry Handbook Committee’s intention to make the handbook
similar to ACI 318-05. It was the original intention to
include defnitions in this chapter, but the committee considered it more user riendly to include defnitions either at
the beginning o each chapter or in the text where a term is
used. It is important to recognize that notations identical to
those used in ACI 318-05 are identifed wi th “(ACI)” ater
the defnition.
Chapter 3—Preliminary Design
of Precast/Prestressed
Concrete Structures
This chapter was chapter 2 in the sixth edition.
The load tables in the chapter have been updated to meet
the latest ACI 318-05, IBC 2006, and ASCE 7-05 provisions. Load capacities have not changed signicantly,
except for short-span components where reduced phi factors φ in the prestressed transfer zone govern the design.
Preliminary Design Aids for several new products have
been added to the seventh edition, including section 3.3.11
and Design Aid 3.12.10 for use in sizing precast concrete
This chapter was chapter 3 in the sixth edition.
The ASCE 7-05 update or seismic systems includes an
alternate equation or the determination o the approximate
building period or shear-wall structures. The change to the
requirements and actors or redundancy or high-seismic
design categories is discussed. The discussion o recommended loads or diaphragm design has been updated in an
eort to clariy the dierence between a diaphragm overstrength actor Ψ and the system overstrength actor Ω0.
The new, more prescriptive requirement or a positive
horizontal connection orce parallel to supported components in ASCE 7-05 section 12.1.4 is discussed as part o
updated inormation on structural integrity.
Some advanced results rom the PCI-sponsored volumechange study have also been included. 11
The design examples or moment-resisting rames are covered in more detail in the PCI Seismic Design Manual,12 published in 2007, and are no longer repeated in the handbook.
PCI Journal
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133
a
b
c
d
f
e
g
h
Figure 2. Typical products o the industry.
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i
Figure 3. Collector orce demand diagram or shear walls in a parking garage. See note a in Postpublication Notes at the end o this article.
Examples or shear-wall buildings and or precast
concrete diaphragms have been updated to clariy
diaphragm and collector design procedures. Diaphragm
design has been expanded, and more detail is provided
or collectors.
Figures 3 and 4 illustrate the intent o ASCE 7-05 and IBC
2006.
An entirely new section (section 4.9) on blast-resist ant
design has been added to the chapter. This section discusses the special considerations o large-magnitude,
Figure 4. Perspective view o shear wall and collectors.
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135
Table 2. Recommended shear-riction coecients (6th edition)
Crack interface condition
Recommended µ
Maximum µe
Maximum Vu = φVn
1. Concrete to concrete, cast
monolithically
1.4λ
3.4
2. Concrete to hardened concrete,
with roughened surace
1.0λ
2.9
0.25λ2f 'c Acr ≤ 1000 λ2Acr
3. Concrete to concrete
0.6λ
2.2
0.20 λ2f'c Acr ≤ 800λ2Acr
4. Concrete to steel
0.7λ
2.4
0.20λ2f 'c Acr ≤ 1000 λ2Acr
0.30λ2f 'c Acr ≤ 1000 λ2Acr
Table 3. Recommended shear-riction coecients (7th edition)
Case
Crack interface condition
µa
Maximum µe
Maximum Vu /φ
1
Concrete to concrete, cast monolithically
1.4λ
3.4
0.30λf'c Acr ≤ 1000λAcr
2
Concrete to hardened concrete, with roughened
surace
1.0λ
2.9
0.25λf'c Acr ≤ 1000λAcr
3
Concrete placed against hardened concrete not
intentionally roughened
0.6λ
Not applicableb
0.20 λf 'c Acr ≤ 800λAcr
4
Concrete to steel
0.7λ
Not applicableb
c
0.20 λf 'c Acr ≤ 1000λAcr
a. In accordance with ACI 318-05 Section 11.7.4.3.
b. The use o µe is not applicable or concrete placed against hardened concrete not intentionally roughened or against steel.
c. The handbook shows this as 0.30λf 'c Acr ≤ 1000 λAcr. This is incorrect. It should be 0.20λf 'c Acr ≤ 1000λAcr.
short-duration loads on precast concrete systems wit h large
mass and inertia. Topics include blast loads, dynamic material properties, and blast-design methods. A blast-design
example or a cladding panel is also included.
Chapter 5—Design of Precast
and Prestressed Concrete
Components
This chapter was chapter 4 in the sixth edition.
Section 5.2.3 and example 5.2.3.2 have been revised to allow for the use of an interpolated phi factor φ for underdeveloped strand in accordance with ACI 318-05 section
12.9.1. This section and the example show that for the exural analysis of a section with fully and partially developed
strand, the partially developed strands will maintain their
load when strained beyond the slipping strain. See note b
in Postpublication Notes at the end of this article.
Section 5.2.5 has been signicantly expanded to increase
design guidelines and provide a complete design example
for stadium-seating components.
13
Based on a review of the original research, section 5.3.6
has been revised to correct the equation for the effective
shear friction coefcient (Eq. [5-33]) to include the phi
factor φ in the numerator. Also, based on this review of
136
Fall 2010
| PCI Journal
the original research, use of the effective coefcient of
friction with concrete placed against hardened concrete not
intentionally roughened and concrete-to-steel interfaces
has been disallowed, and the formulas for maximum shear
stress (right column of Table 4.3.6.1 in the sixth edition)
have been revised to remove the squared from the lambda
λ terms. Other sections using shear friction have been
updated to be consistent with these revisions.
A comparison of the sixth-edition and seventh-edition
tables is shown in Tables 2 and 3.
Based on recent experience with self-consolidating
concrete (SCC) in which the surface remained slick after
curing, a warning has been included regarding selection of
the appropriate interface condition when corbels are cast
on the up face of components cast using SCC.
In section 4.5 of the sixth edition, Beams with Ledges, the
table for ledge design m factors has been removed because
the committee felt that solving Eq. (5-52) of the seventh
edition is as easy as looking up a value for m in the chart.
Also, Fig. 5.5.3 includes corrections for determining the
m factor for an inverted-tee beam based on the original
research.14
Concerns raised by PCI Professional Members suggested
the need for better clarity of the detailing requirements for
dap-ended members. Accordingly, the committee modied
Fig. 5.6.3 by enlarging the alternative dap reinforcement
detail to clarify and emphasize the importance of dap rein forcement detailing and placement.
Chapter 6—Design of
Connections
Section 5.8, Camber and Deection, was expanded, primarily to provide guidance for the use of ACI 318-05 Table
9.5(b) Maximum Permissible Computed Deections ( PCI
Design Handbook Table 5.8.1).
Tables 4 and 5 (Tables 6.2.1 and 6.2.2 in the seventhedition PCI Design Handbook ) have been added to clariy
overstrength actors applicable or diaphragms and collector systems, respectively.
Section 5.9, Compression Components, contains several
signicant revisions. In section 5.9.1, the section allowing elimination of lateral ties in certain instances based
on Recommended Practice for the Design of Prestressed
Concrete Columns and Walls 15 has been removed because
the reference no longer contains these exceptions.
Section 6.4.3.1, Reinorcing Bars in Conduit, has added
requirements or supplemental reinorcement based on the
previous research.18
In Example 5.9.1.1, the interaction curve has been modied to better show its actual shape.
In Example 5.9.3.1, the stiffness-reduction factor has been
changed to ΦK = 0.85, as suggested by ACI 318-05 section
R10.11.1.
Section 6.2.3 has been added to dierentiate IBC 2006
requirements rom recommended PCI values or seismic
overstrength actors or lateral-orce-resisting systems.
Table 6.5.5, Summary table o HCA (headed concrete
anchors) group concrete shear strength equations, has been
added to conveniently show the appropriate design actor
or each ailure mode.
Design Example 6.5.5.4, Design o Bearing Seat with
Headed Concrete Anchors (Example 6.5.8.1 in the sixth
edition), has been modifed to include the weld requirements or the bearing seat, and a table has been added that
shows all o the component design strengths.
Section 5.9.4, Concrete Brackets or Corbels, has been
moved into this chapter from chapter 6, Design of Connec tions, in the sixth edition, on the basis that this is part of
the component design rather than a connection.
Further explanation o the interaction o tension and shear
or headed concrete anchors has been added to section
6.5.8, Interaction o Tension and Shear.
Section 5.10, Shear Walls, is a completely new section. It
provides an introduction to the design of precast concrete
shear walls, including a design example.
Examples 6.6.5.1(a) and 6.6.5.1(b) are new and illustrate
the design procedure or an unstiened connection angle
using headed concrete anchors and bolts, respectively.
Section 5.11, Sandwich Panels, was moved into this chapter from chapter 9 of the sixth edition, Thermal, Acoustical,
Fire and other Considerations, because it is an important
aspect of many precast concrete structures and is more ap propriate with a discussion about component design.
Section 6.7.2.1, Fillet Welds, has been modifed to more
accurately represent the nominal design strength o a fllet
weld element. This section now includes the eect o the
angle o loading with respect to the axis o the weld element.
Section 5.12.1, Point Loads on Double-Tee Flanges, is a
new section, though the design example was in the Analysis Using Strain Compatibility subsection of the Flexure
section of the sixth edition. Determination of the effective
resisting width for a point load has been revised to more
accurately reect load test data. 16
Enhancement has been added to the Instantaneous Center
Method (ICM) or weld design in section 6.7.5.2 t o more
clearly demonstrate the design approach.
Section 5.12.7, Warping of Deck Components, is a completely new section. It addresses the warping of doubletees, especially in parking structures, to obtain desired
drainage patterns. Recommendations are based on experience and relatively recent research. 17
Design Aid 5.14.15 now provides updated corbel capacities
and more clearly illustrates whether the capacity is limited
by exure, shear, or maximum Vu.
Chapter 5 modifed the calculation o eective shear riction, and this revision has been applied to the chapter 6
design examples, where appropriate.
Cazaly Hanger, section 6.9.1, has been modifed to reect
recent research indicating that previous editions may not
have been adequately conservative. While the procedure is
essentially the same, an additional requirement or anchor
reinorcement has been introduced to avoid a concrete
breakout ailure (Fig. 5). This is illustrated below.
PCI Journal
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Table 4. Diaphragm overstrength actorsa
Seismic design category
Ψ factor table design element
A
B
C
D
E
F
Bearing-wall systems
1
1
2.5 a
2.5a
2.5a
2.5a
Building-rame systems
1
1
2.5a
2.5a
2.5a
2.5a
Moment-resisting systems
1
1
2.5 a
3a
3a
3a
Dual system with special moment rames
1
1
2.5 a
2.5a
2.5a
2.5a
Dual system with intermediate moment rames
1
1
2.5a
2.5a
2.5a
2.5a
Inverted pendulum system and cantilevered-column systems
1
1
2.5a
2
2
2
Bearing-wall systems
1
1
1b
2
2
2
Building-rame systems
1
1
1b
2
2
2
Moment-resisting systems
1
1
1b
1
1
1
Inverted-pendulum system and cantilevered-column systems
1
1
1b
1
1
1
Bearing-wall systems
1
1
1b
2
2
2
Building-rame systems
1
1
1b
2
2
2
Moment-resisting systems
1
1
1b
1
1
1
Inverted-pendulum system and cantilevered-column systems
1
1
1b
1
1
1
Diaphragm to SFRS connection
Diaphragm chord element
Diaphragm joint shear connection
a. The tabulated value o the diaphragm overstrength actor Ψ may be reduced by subtracting 0.5 or structures with fexible dia phragms but shall not
be taken as less than 2.0 or any structure.
b. For seismic design category C diaphragms, it has been assumed that the maximum distributed design orce at that l evel is used.
Section 6.13, Typical Connections, has been added to
represent typical connection details used in total precast
concrete structures.
Example 6.13.6, Wall-to-Wall Shear Connection with Combined Loading, is new and illustrates a combined shear and
tension connection and the interaction equations or each
component and the capacity region o the assembly.
Example 6.13.8, Deormed Bar or Reinorcing Bar Connection Plate Supporting Steel Beam, is new and illustrates
a typical connection or a steel, wide-ange beam connected to a plate with deormed bar anchors. See note c in
Postpublication Notes at the end o this article.
Design Aids 6.15.4 and 6.15.5 no longer show weld size
and minimum plate thickness requirements or welds using E70 electrodes or ASTM Grade 60 reinorcing bars
because this is no longer allowed by AWS D1.4. 19
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Table 5. Seismic overstrength actorsa
Seismic design category
Ωo factor table design element
A
B
Cb
Db
Eb
Fb
Bearing-wall systems
1
1
2.5
2.5
2.5
2.5
Building-rame systems
1
1
2.5
2.5
2.5
2.5
Moment-resisting systems
1
1
3
3
3
3
Dual system with special moment rames
1
1
2.5
2.5
2.5
2.5
Dual system with intermediate moment rames
1
1
2.5
2.5
2.5
2.5
Inverted-pendulum system and cantilevered-column systems
1
1
1.25
1.25
1.25
1.25
Bearing-wall systems
1
1
2.5
2.5
2.5
2.5
Building-rame systems
1
1
2.5
2.5
2.5
2.5
Moment-resisting systems
1
1
3
3
3
3
Dual system with special moment rames
1
1
2.5
2.5
2.5
2.5
Dual system with intermediate moment rames
1
1
2.5
2.5
2.5
2.5
Inverted-pendulum system and cantilevered-column systems
1
1
1.25
1.25
1.25
1.25
Collectors (drag-ties)
Collectors (drag-tie) transfer to vertical resisting element
a. Table shown is condensed rom ASCE 7-05, Table 12.2-1.
b. The tabulated value o the system overstrength actor Ωo may be reduced by subtracting 0.5 or structures with fexible di aphragms but shall not be
taken as less than 2.0 or any structure.
Figure 5. Cazaly hanger.
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139
Figure 6. Cladding panel connection concepts—seismic drit eect (translating panels).
Chapter 7—Structural
Considerations for
Architectural Precast
Concrete
— Example 7.5.3.1, Architectural Precast Concrete Panel with Earthquake Loading. This
example is the same as Example 3.2.4.2 in the
sixth edition, but has been expanded to reect appropriate seismic actors. It includes comparisons
o critical loads rom the two previous wind-load
examples to illustrate the actual design procedure
that an engineer would use.
This chapter is very much like its counterpart in the sixth
edition, with several noteworthy additions:
•
•
It includes material rom the third edition o PCI’s
Architectural Precast Concrete,20 published in 2007,
that is particularly important or a structural engineer
designing architectural precast concrete to know.
Three examples have been added. All three use the
same cladding panel on the same building but consider
dierent load conditions. The load cases are:
— Example 7.5.1.1, Use of ASCE 7 Method 1 for
Wind-Load Determination. This is an extension
o Example 4.2.3.1, which uses ASCE 7-05 to
calculate wind loads on a building to design or
the lateral-load-resisting-system. The example
in this chapter covers the individual panels as a
cladding component.
— Example 7.5.2.1, Use of ASCE 7 Method 2 for
Wind-Load Determination. This example was
added because Method 1 has a building height
restriction o 60 t (18 m) and many architectural
cladding components are used on taller buildings.
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| PCI Journal
•
•
Seismic drit considerations have been added to illustrate the need or some connections to move in
dierent directions to avoid unintended orces acting
on the cladding and/or the supporting structure. This is
illustrated in Fig. 6.
The chapter has added recommendations or where
to locate connections on cladding panels to provide
predictable behavior. This is illustrated in Fig. 7.
Chapter 8—Component
Handling and Erection Bracing
This was chapter 5 in the sixth edition.
The new section 8.3.3, Spreader Beams, has been added to
provide guidance or the design o spreader beams used in
handling precast concrete components.
Section 8.6, Erection Handling, has been revised to address uncontrolled rolling when erecting wall panels with
three-point pick using rolling blocks between the two
bottom liting points. Some erectors and engineers have
Figure 8. Stability during erection.
Figure 7. Typical cladding connection locations.
observed frsthand that the equation shown in Fig. 5.6.2
o the sixth edition or the distance rom the lower rolling
block to the center o gravity is incorrect. This is shown in
Fig. 8. A paper written by Don Logan, P.E., in the Winter
2010 PCI Journal21 explains in detail the potential risks
associated with using this equation. As a result, the Industry Handbook Committee has recommended the rigging
arrangement illustrated in Fig. 9 to avoid this condition.
Section 8.7, Erection Bracing, was reduced to an abbreviated version, and design examples were removed. This was
a topic that was debated signifcantly by the Industry Handbook Committee, primarily as a result o the dierence
between the experiences o the committee members and
the requirements o ASCE 37-02 Design Loads on Structures During Construction.22 It was concluded that because
ASCE 37-02 is not a mandatory code, the loads imposed
on precast concrete structures during erection should be the
responsibility o the experienced precast concrete designer.
With that responsibility must go the authority t o defne the
loading requirements during this temporary stage.
Chapter 9—Precast and
Prestressed Concrete:
Materials
Chapter 9 is a new chapter dealing exclusively with materials aecting and used in precast and prestressed concrete
construction. Chapter 9 represents a consolidation o
several material sections that were contained in various
chapters o past handbook editions. Major topics include
concrete, grouts, connection materials, corrosion protec-
Figure 9. Stability during erection.
tion, reinorcement, waterproofng, and in-service repairs.
The chapter also includes a number o new fgures, graphs,
and tables to augment the text.
Because the handbook is oten used as a textbook at the
university level and many students have not been exposed
to typical materials used in the industry, several photographs have been included—or example, prestressing
strand (Fig. 10) and standard reinorcement ( Fig. 11).
Section 9.2, Concrete, covers the constituent materials o
the concrete matrix, consisting o cement, supplementary
cementitious materials (SCMs), aggregates, admixtures,
and pigments. Detailed descriptions are provided with
relevant reerences to ASTM standards. Physical properties
o concrete are introduced, such as compressive and tensile
strength, modulus o elasticity, volume changes, and
durability. Tables presenting common material parameters
are given and photographs o good concrete and common
deterioration mechanisms are presented, as illustrated in
Fig. 12 and 13, respectively.
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141
Figure 10. Wire prestressing strand o various sizes.
Figure 13. Planar cracking marking reezing and thawing damage.
viding protection against deterioration are covered within
the context o waterproofng with coatings, joint sealant
types and issues, and expansion joint sealant systems.
Figure 11. Reinorcing bars o various sizes, rom no. 18 to no. 3.
In the event that a precast concrete component is damaged
during transportation or erection, in-service repairs are
reviewed. Other in-service conditions are also examined,
and suggested maintenance and strengthening means are
provided.
The chapter concludes with section 9.9, Relevant Standards and Publications, which is a comprehensive listing
o reerence standards and publications relevant to materials. These standards may also appear in project specifcations prepared by the engineer o record or architect o
record.
Chapter 10—Design for Fire
Resistance of Precast and
Prestressed Concrete
Figure 12. Example o good air-void system.
Section 9.4, Connection Materials, reviews the common
steel sections, bearing pads, and bolts used in connections.
This is ollowed by a discussion on the galvanic series and
its importance in examining service lie and protection o
connections. Protection means are discussed, including
painted systems, galvanized steel, and stainless steel, and
the proper means o speciying them.
Section 9.6, Reinorcement, describes various systems
or precast and prestressed concrete components and the
various deterioration mechanisms that can occur. Dierent
means o embedded steel protection are presented to mitigate common deterioration problems. Other means o pro-
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This was section 9.3 in the sixth edition and is now a
standalone chapter to emphasize the many benefts o precast concrete in fre protection.
Section 10.6.2, Continuous Components (section 9.3.7.2,
Continuous Members, in the sixth editi on), has been shortened by eliminating other loading conditions beyond the
two-span case discussed. Reer to PCI MNL-124-8923 or
additional load case discussion.
Example 9.3.7.1, Fire Endurance or Hollow-Core Slab
with Topping, rom the sixth edition has been eliminated
because most applications or residential use do not use
topping and still satisy fre-endurance requirements.
Example 10.8.1, Fire Endurance by Code Tables, or a
double-tee with topping, has been updated to reect IBC
2006.
A new section 10.8, Requirements or Parking Structures,
has been added to assist the user in applying the requirements and tables in IBC 2006 to the design o precast and
prestressed concrete components typically used in parking
structures. Several paragraphs that outline recent research
at Lehigh University are included in this section. This
research was perormed to evaluate realistic vehicle-fre
loads (time-temperature or time-heat ux relationships) or
precast concrete parking structures. This work investigated
the inuence o the structural geometry and fre characteristics on the resulting fre load.
Chapter 11—Thermal and
Acoustical Properties of
Precast Concrete
The topics o chapter 11 comprise sections 9.1 and 9.2
rom the sixth edition. The chapter provides updated inormation on both topics, as well as adding design guidelines
or calculating the thermal resistance o sandwich panels
using metal ties between concrete wythes.
Chapter 12—Vibration Design
of Precast/Prestressed
Concrete Floor Systems
This was section 9.7 in the sixth edition and is now a
standalone chapter to demonstrate the importance o vibration control in certain types o acilities. There are no signifcant changes; however, a minor change is the addition
o three double-tee sections to Fig. 12.4.1 (Fig. 14). They
are 12DT28+2, 12DT30, and 15DT34.
Chapter 13—Tolerances for
Precast and Prestressed
Concrete
Chapter 13 in the seventh edition was chapter 8 in the sixth
edition. It was moved to accommodate other major changes
in the layout o the PCI Design Handbook . The only other
changes are editorial and correction o some minor errors.
Chapter 14—Specifications
and Standard Practices
This chapter was chapter 10 in the sixth edition.
The most signifcant change rom the previous edition was
the reorganization o the sections. PCI St andard Design
Practice (section 14.1) has been placed frst because it
is believed to be the most important inormation or the
Figure 14. Natural requency o selected foor units.
PCI Journal
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143
designer in the chapter. It has been updated to reect ACI
318-05 and has had extensive review by the PC I Building
Code Committee and TAC.
Sections 14.2 and 14.3 are brie descripti ons o the guide
specifcations or structural and architectural precast
concrete, respectively. They have both been updated to
the latest ACI 301 and AIA Masterspec.24,25 The ull guide
specifcations are on the CD in the ront jacket pocket o
the PCI Design Handbook and are in a usable word-processing ormat.
Appendix—Impact of
ACI 318-08 on this Handbook
The appendix is totally new and is the result o PCI’s TAC
directing that the impact o ACI 318-08 27 be included in the
seventh edition. It is based entirely on our papers written by
S. K. Ghosh and published as a supplement to separate issues
o the PCI Journal.28–31 The PCI Industry Handbook Committee reviewed those papers and included in the appendix those
portions that have an impact on sections o the handbook.
Conclusion
Section 14.4, Standard Operations Practice Recommendations or Precast Concrete, has been updated to reect
current practices in the industry.
Section 14.5, Recommendations on Responsibility or
Design and Construction o Precast Concrete Structures,
remains essentially the same as in the sixth edition.
Chapter 15—General Design
Information
This chapter was chapter 11 in the sixth edition.
The ollowing is a listing o the most signifcant changes in
this chapter:
•
•
•
•
•
All Design Aids have been reorganized to better reect
the topic.
All Design Aids have been updated to reerence the
current model codes and standards. Numerical values
have been modifed where required. For example, the
uniorm oor loading in passenger-car parking structures was revised rom 50 lb/t 2 (244 kg/m2) to 40 lb/t2
(195 kg/m2).
The sixth-edition Design Aid 11.2.1 has been omitted
rom the seventh edition because it is easy to calculate
the values that are a unction o the concrete strength.
The sixth-edition Design Aid 11.2.2 has been updated
in the seventh edition as Design Aid 15.2.1 to include
the recommended curves using two recognized equations or the modulus o elasticity o concrete.
144
Chapter 2, Notations, was intended to include defnitions
used throughout the handbook, as well as other te rms
typically used in the industry that might not be specifcally
used in the handbook. Terms such as down-in-orm, chuck,
stripping, dunnage , and the like are used in everyday
conversation in plants and may be helpul or the inexperienced designer or student using the handbook.
A review o chapter 2 also resulted in the observation that
the notation used in the handbook could be improved with
a complete overhaul. Many o the same notations have
dierent meanings, which can cause conusion. Examples
include the notation R, which is the response modifcation
actor or seismic design in chapter 4 and the thermal resistance o a precast concrete component in chapter 11.
There are numerous less-critical topics and suggested
changes brought orward or consideration, but the decision to incorporate them was postponed because o t iming
and publishing constraints. Similar thoughts occurred
during the blue-ribbon review. The committee has gathered these items or uture consideration and has provided
them to the next PCI Industry Handbook Committee, to be
chaired by Tim Salmons, P.E., S.E. The list o items or the
eighth edition o the PCI Industry Handbook Committee to
address also includes:
•
The new seventh-edition Design Aid 15.4.2 has
been added and includes typical bent reinorcing bar
confgurations and designations. The source or this
inormation is ACI’s publication Details and Detailing
o Concrete Reinorcement.26
•
Most o the goals established by the PCI Industry Handbook Committee or the seventh edition have been accomplished. However, several were not and will remain goals
or the eighth edition, as noted in the ollowing paragraphs.
The new seventh-edition Design Aid 15.5.4 has been
added and illustrates common styles o welded-wire
reinorcement (WWR) shear reinorcement used in the
ends o double-tee stems.
Fall 2010
| PCI Journal
•
•
ACI 318 intends a major revision in 2013, with only
an interim revision in 2011. PCI’s TAC will direct the
PCI Industry Handbook Committee as to which versions o ACI 318, IBC, and ASCE will be used or the
eighth edition.
Consider making the publication a t wo-volume set,
with one including material that does not necessarily
change with the code cycles.
Use 3 in. (75 mm) topping or double-tee load tables
instead o 2 in. (50 mm).
•
•
•
Reintroduce material related to erection bracing and
include examples.
3.
Quality Control or Plants and Production o Structural Precast Concrete Products. MNL-116-99. 4th
Create a uniorm ormat or all examples and all fgures.
Consider providing a fnal drat o the eighth e dition
to the entire engineering community or public comment. While the seventh edition has had a very intense
review process, it cannot be considered a consensus
document. Responding to public comments would allow the document to achieve this status.
ed. Chicago, IL: PCI.
4.
3rd ed. Chicago, IL: PCI.
Update the handbook to reect ongoing research.
As stated in the oreword, the PCI Design Handbook is a
living document. Comments related to any aspect o the
handbook are encouraged and much appreciated. This
handbook has had a very intensive review at several levels.
It must be understood, however, that all errors may not
have been observed and corrected during these reviews.
PCI thereore intends to publish errata based on input o
the users o the handbook over the next several months.
The errata will also be posted on PCI’s website at
www.pci.org. Address all comments to PCI’s Managing
Director o Technical Activities at PCI, Jason Krohn, 200
West Adams Street, Suite 2100, Chicago, IL 60606.
a.
b.
c.
Figure 4.8.4 o the seventh edition is not correct in that
the horizontal line just above the lower shear wall on
the right side o the plan should line up with the end o
that shear wall. Figure 3 in this article is correct.
Example 5.2.3.2 does not correctly reect the text o
the seventh edition in that it does not properly account
or load in the partially developed strands.
Use o E70 electrodes has been a common practice
in the industry or years. The statement that this is no
longer allowed by AWS D1.4 is incorrect. Reer to the
sixth-edition PCI Design Handbook , which is correct.
References
1.
2.
PCI Industry Handbook Committee. 2010. PCI Design
Handbook: Precast and Prestressed Concrete. MNL120-10. 7th ed. Chicago, IL: PCI.
American Concrete Institute (ACI) Committee 318.
2005. Building Code Requirements or Structural Con-
PCI Glass Fiber Reinorced Concrete Panels Committee. 2009. Manual or Quality Control or Plants
and Production o Glass-Fiber Reinorced Concrete
Products . MNL-130-09. Chicago, IL: PCI.
6.
American Society o Civil Engineers (ASCE). 2005.
Minimum Design Loads or Buildings and Other
Structures. Structural Engineering Institute (SEI)/
ASCE 7-05 and Supplement No. 2. Reston, VA:
ASCE.
7.
International Code Council. 2006. International Building Code 2006 . Falls Church, VA: ICC.
8.
PCI Bridge Design Manual Steering Committee. 1997.
Precast Prestressed Concrete Bridge Design Manual .
MNL-133-97. 1st ed. Chicago, IL: PCI.
9.
PCI. 1981. Reections on the Beginnings o Prestressed Concrete in America. Chicago, IL: PCI.
Postpublication Notes
Ater publication o the handbook, several errata that aect
this article were observed as ollows. These and other errata will be published in a uture issue o the PCI Journal.
PCI Architectural Precast Concrete Services Committee and Plant Certifcation Committee. 1996. Manual
or Quality Control or Plants and Production o Architectural Precast Concrete Products. MNL-117-96.
5.
•
PCI Plant Certifcation Committee. 1999. Manual or
10. Schutt, Craig, ed. 2004. PCI 50 Years: Visions Taking
Shape. Chicago, IL: Cherbo Publishing Group Inc.
11. Klein, G. J., and R. J. Lindenberg. 2009. Volume
Change Movement and Forces in Precast Concrete
Buildings. Research report, PCI, Chicago, IL.
12. Cleland, Ned and S. K. Ghosh. 2007. Seismic Design
o Precast/Prestressed Concrete Structures. MNL140-07. Chicago, IL: PCI.
13. Mattock, A. H., W. K. Li, and T. C. Wang. 1976. Shear
Transer in Lightweight Reinorced Concrete. PCI
Journal , V. 32, No. 1 (January–February): pp. 20–39.
14. Klein, G. J. 1986. Design o Spandrel Beams. PCISFRAD project no. 5. PCI Journal, V. 31, No. 5
(September–October): pp.76–124.
15. PCI Committee on Prestressed Concrete Columns.
1988. Recommended Practice or the Design o Prestressed Concrete Columns and Walls. PCI Journal, V.
33, No. 4 (July–August): pp. 56–75.
crete (ACI 318-05) and Commentary (ACI 318R-05).
Farmington Hills, MI: ACI.
16. Aswad, Alex, and George Burnley. 1991. Point Load
PCI Journal
| Fall
2010
145
Tests o Double-Tee Flanges. PCI Journal, V. 36, No.
4 (July–August): pp. 66–73.
17. Mack, P., G. Force, C. Magnesio, and K. Bryan. 2003.
The Practice o Warping Double-Tees. PCI Journal, V.
48, No. 1 (January–February): pp. 32–48.
18. Concrete Technology Associates (CTA). 2000. Ductile
Pullout Connections. CTA Technical Bulletins, Vol. II.
Chicago, IL: PCI.
19. American Welding Society (AWS). 2002. Structural
Welding Code—Reinorcing Steel. AWS D1.4-02.
Miami, FL: AWS.
20. PCI Architectural Precast Concrete Committee. 2007.
Architectural Precast Concrete. MNL-122-07. 3rd ed.
Chicago, IL: PCI.
21. Logan, D. 2010. Erecting Long, Vertical Precast Concrete
Members with One Crane and Two Operating Lines. PCI
Journal, V. 55, No. 1 (Winter): pp. 118–136.
22. American Society o Civil Engineers (ASCE)/Structural Engineering Institute (SEI). 2002. Design Loads
on Structures During Construction. SEI/ASCE 37-02.
Reston, VA: ASCE.
23. PCI Fire Committee. 1989. Design or Fire Resistance
o Precast Prestressed Concrete. MNL-124-89. 2nd
ed. Chicago, IL: PCI.
24. American Institute o Architects. 2006. Masterspec
2004. Salt Lake City, UT: ARCOM.
25. ACI Committee 301. 2010. Specifcations or Structural Concrete. Farmington Hills, MI: ACI.
26. ACI. 1999. Details and Detailing o Concrete Reinorcement. ACI 315-99. Farmington Hills, MI: ACI.
27. ACI Committee 318. 2008. Building Code Requirements or Structural Concrete (ACI 318-08) and Commentary (ACI 318R-08) . Farmington Hills, MI: ACI.
28. Ghosh, S. K. 2008. Signifcant Changes to ACI 318-08
Relative to Precast/Prestressed Concrete: Part 1. PCI
Journal. Suppl. no. 53-2.
29. Ghosh, S. K. 2008. Signifcant Changes to ACI 318-08
Relative to Precast/Prestressed Concrete: Part 2. PCI
Journal. Suppl. no. 53-3.
30. Ghosh, S. K. 2008. Signifcant Changes to ACI 318-08
Relative to Precast/Prestressed Concrete: Part 3. PCI
Journal. Suppl. no. 53-5.
146
Fall 2010
| PCI Journal
31. Ghosh, S. K. 2009. Signifcant Changes to ACI 318-08
Relative to Precast/Prestressed Concrete: Part 4. PCI
Journal . Suppl. no. 54-3.