Pci 7th Edition Discussion

Fal l 2010 | PCI Journal

PCI Industry Handbook Committee

Greg Force, P.E., FPCI, ChairmanNeal S. Anderson, P.E., S.E., FPCI, FACINed M. Cleland, PhD, P.E., FPCI, FACIHarry A. Gleich, P.E., FPCI, FACIGary A. Householder, P.E.Pat Hynes, P.E., FPCIPhillip J. Iverson, P.E.Walter Korkosz, P.E., S.E.Jason Krohn, P.E.Karen Laptas, P.E.David J. Larsen, P.E., S.EJason P. Lien, P.E.Rafael A. Magana, P.E.Michael I. Owings, P.E., S.E.Stephen Pessiki, PhD, FPCI, FACISteven H. Peterson, P.E.Courtney B. Phillips, P.E., S.E.Timothy R. Salmons, P.E., S.E.Kim E. Seeber, P.E., FPCILarbi Sennour, PhD, P.E., FPCI, FACIFattah Shaikha, PhD, P.E., FPCIIrwin J. Speyer, P.E., FPCI, FACIPeter G. Troiani, P.E., S.E.Helmuth Wilden, P.E., FPCICharles E. Wynings, P.E.

a. Deceased January 10, 2008

Consulting Members

Robert F. Mast, P.E., S.E., FPCI, HACIJagdish C. Nijhawan, P.E., FPCIJ. Robert Norris, P.E.

Editor

Helmuth Wilden, P.E., FPCI

Background and Discussion PCI DESIGN HANDBOOK

PRECAST AND PRESTRESSED CONCRETE

7th Edition

Prepared by

PCI Industry Handbook Committee

Foreword

The Precast/Prestressed Concrete Institute (PCI) updates and publishes the PCI Design Handbook: Precast and Prestressed Concrete1 in cycles coincident with publica-tion of the American Concrete Institute’s (ACI’s) Building Code Requirements for Structural Concrete (ACI 318-05) and Commentary (ACI 318R-05).2 The seventh edition of the PCI Design Handbook, published in 2010, continues that tradition. Each update of the PCI Design Handbook reflects the modifications adopted by ACI 318 as well as the most recent research and experience of designers regularly engaged in the design of precast and prestressed concrete structures.

Introduction

The publication of the seventh edition of the PCI Design Handbook continues to meet the goals set forth by the Pre-cast/Prestressed Concrete Institute, which was established in 1954 as the Prestressed Concrete Institute. The current name was adopted in 1989 to better reflect the interests of both prestressed concrete producers and those that manu-facture nonprestressed precast concrete components. The goal is to advance the design, manufacture, and use of precast and prestressed concrete.

The seventh-edition PCI Design Handbook’s primary objective remains the same as it was with the first edition, published in 1971; that is, “… to make it easier for archi-tects 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.”

The seventh edition of the PCI Design Handbook back-ground and discussion paper is the sixth document of its type. The first was published for the second-edition PCI

129

Fal l 2010 | PCI Journal130

• It includes the correction of errors in the sixth edition that were published as errata in the May–June 2007 issue of the PCI Journal.

• 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 updated information based on current stan-dard practices of the industry.

• It includes updated information based on results of recent research in the industry.

• It expands text of selected topics to provide more-comprehensive discussion.

• Selected text, figures, tables, Design Aids, and ex-amples are rewritten, modified, and edited for improved clarity.

The user of the PCI Design Handbook will observe several somewhat subtle differences from the sixth edition:

• Equations are numbered consecutively in each chapter. For example, Eq. 6.5.2.1 in the sixth edition is now Eq. (6-2) and Eq. 6.12.1.1 is now Eq. (6-93).

• A complete list of design examples is included at the end of the foreword to the handbook.

• Previous charts shown as figures are now Design Aids, and a complete list is included at the end of the fore-word to the handbook.

• All figures and tables are identified 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 first digit refers to the chapter, the second digit refers to the main section in which the figure or table appears, and the third digit represents the consecutive order in the main section.

• Chapters are identified on each page with a tab box at the edge of the page for easy reference.

• 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 for chapter 5 of the seventh-edition PCI Design Handbook.

• For the most part, American Concrete Institute nomen-clature and formatting has been used.

The user will also observe that some sections of the sixth edi-tion have been omitted from the seventh edition. They are:

Design Handbook and was an authored paper titled “Back-ground and Discussion on PCI Design Handbook, Second Edition.” It was published in the January–February 1980 issue of the PCI Journal. Subsequent papers with the same intent and similar titles were published as follows:

• For the third-edition PCI Design Handbook: May–June 1988, PCI Journal

• For the fourth-edition PCI Design Handbook: Novem-ber–December 1996, PCI Journal

• For the fifth-edition PCI Design Handbook: July–Au-gust 1998, PCI Journal

• For the sixth-edition PCI Design Handbook: March–April 2006, PCI Journal

Purpose

The main purpose of the background and discussion of the seventh edition of the PCI Design Handbook is to identify significant changes from the sixth edition on a chapter-by-chapter basis and explain the rationale for these changes. Other purposes are to describe current work in progress toward the eighth edition of the PCI Design Handbook and to establish goals for future work.

Synopsis of changes from the sixth-edition PCI Design Handbook

Some things in the seventh-edition PCI Design Handbook remain unchanged from the sixth edition. The number of chapters has been increased from 11 to 15 as a result of the PCI Industry Handbook Committee’s intent to provide more emphasis on some topics, including fire endurance and vibrations. Chapter 9, Precast and Prestressed Concrete: Ma-terials, is totally new and compiles discussions of materials that were in individual chapters in previous editions. Chapter 2 is also totally new and includes the notation used through-out the entire handbook on a chapter-by-chapter basis.

Table 1 outlines the differences from the sixth edition to the seventh edition of the PCI Design Handbook.

The seventh edition of the PCI Design Handbook, while similar to the sixth edition in many ways, incorporates modifications that generally fall into one of the following categories:

• It includes updated information reflecting changes from ACI 318-02 to ACI 318-05, incorporating new and revised provisions. Note that changes related to ACI 318-08 are identified in the appendix to the sev-enth edition.

131PCI Journal | Fal l 2010 131

information is available in other publications.

• Section 9.10, Coordination with Mechanical, Electri-cal and Other Sub-Systems. At the time of publication of the seventh edition, it was the intent of PCI to de-velop a recommended practice and guidelines for total precast concrete structures and the committee con-sidered that this new publication would provide more information than could be included in the handbook.

• Section 9.5, Quality Assurance and Control. The com-mittee felt that this section was redundant because three major PCI quality-control manuals already exist. They are MNL-1163 for structural precast concrete, MNL-1174 for architectural precast concrete, and MNL-1305 for glass-fiber-reinforced concrete.

• Section 9.9, Precast Segmental Construction. This top-ic is outside the area of building construction, which is the emphasis of the handbook, and more up-to-date

Table 1. Comparison of 6th and 7th editions of the PCI Design Handbook

Sixth edition Seventh edition

Chapter Pages Figures TablesDesign

examplesDesign

AidsPages Figures Tables

Design examples

Design Aids

1 32 58 5 n.a. n.a. 28 63 n.a. n.a. n.a.

2 New n.a. n.a. n.a. n.a. n.a. 18 n.a. n.a. n.a. n.a.

3Ch. 2 in 6th

58 8 32 n.a. 8 64 8 32 n.a. 11

4Ch. 3 in 6th

124 20 2 19 26 98 34 4 13 26

5Ch. 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.

8Ch. 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.

10Sect. 9.3 in 6th

26 19 13 5 n.a. 26 17 13 4 n.a.

11Sects. 9.1 and 9.2 in 6th

23 4 15 4 n.a. 26 4 15 4 n.a.

12Sect. 9.7 in 6th

8 2 3 3 n.a. 10 2 3 3 n.a.

13Ch. 8 in 6th

34 6 13 2 n.a. 34 6 11 2 n.a.

14Ch. 10 in 6th

36 n.a. n.a. n.a. n.a. 36 n.a. n.a. n.a. n.a.

15Ch. 11 in 6th

58 n.a. n.a. n.a. 31 62 n.a. n.a. n.a. 37

Appendix New n.a. n.a. n.a. n.a. n.a. 22 6 8 n.a. n.a.

Totals 691 223 103 105 94 776 278 115 107 103


9. Based on these approved versions, a blue-ribbon-review version was created. This final review phase consisted of the Blue Ribbon Review Committee, made up of plant engineers, specialty engineers, consulting engineers, academics, and associate members. Each member of the Blue Ribbon Review Committee is a recognized leader in the analysis and design of precast and prestressed concrete structures or an expert in a closely related field. The members of the Blue Ribbon Review Committee are noted in the foreword to the handbook. After a six-week review period, this group met for three days and offered valuable comments that were considered by the Industry Handbook Committee. Most were accepted as improving the publication. Others will be considered as new busi-ness for the eighth edition.

10. A final version of each chapter was then created and reviewed thoroughly by the original chapter subgroup. This review resulted in a few corrections and further improvement.

11. In addition, a comprehensive editorial and technical review of the handbook was carried out by the PCI Publications Department, led by Emily Lorenz, editor-in-chief of the PCI Journal, as well as Jason Krohn, PCI’s Managing Director of Technical Activities.

It is commendable that the seventh edition of the PCI Design Handbook was created primarily through the volunteer efforts of the committee members and many oth-ers. Thousands of hours were devoted to its development, which, at normal consulting rates, would easily exceed a value of $2 million.

The following presents a chapter-by-chapter review of the contents, outlining the general content and emphasiz-ing changes from 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 of the hand-book with a general understanding of the many applica-tions of precast and prestressed concrete used in buildings and other structures. (For bridges, a separate publication by PCI, the Precast Prestressed Concrete Bridge Design Manual,8 should be consulted.)

As is typical with each new edition of the PCI Design Hand-book, the photographs have been updated to illustrate the current state of the art. As a result of the newer photographs, captions and text referring to the photographs have been updated. Although the handbook is not intended for bridges, a photograph of the Walnut Lane Memorial Bridge (Fig. 1) has been retained to remind the user of the beginning of

The handbook committee process

It is of interest to review the process by which the seventh edition of 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 of 25 full members and 3 consulting members. Eighteen of 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 trade-association engineers, and 2 academics.

The process used was as follows:

1. The committee used the sixth edition as the baseline, with the understanding that ACI 318-05, American Society of Civil Engineers (ASCE) 7-05,6 and Interna-tional Building Code 2006 (IBC 2006)7 would be the relevant references for the seventh edition.

2. The committee agreed on a new arrangement, increas-ing the number of chapters from 11 to 15, as described later in this article.

3. A subgroup of three to seven members (including a chairperson) was established for each chapter. The objective of each chapter subgroup was to perform a detailed review of the existing chapter and an exhaus-tive review of research and publications relevant to the subject of the chapter subsequent to the sixth edition.

4. After analysis of information discovered in the sub-groups’ reviews and discussion regarding improved and/or updated content, each subgroup developed a draft of its respective chapter.

5. Each chapter was then edited by the editor, and a committee-ballot version was created.

6. Each chapter was balloted by the committee, and all comments were resolved during meetings of the full committee. This process included 14 face-to-face meetings and 9 web-based teleconferences over the four-year course of development. The intensity peaked during 2009 with two face-to-face meetings and all nine of the teleconferences. In addition, hundreds of individual telephone calls and thousands of emails be-tween members and to and from the editor took place.

7. Additional editing was done, and a Technical Activi-ties Council (TAC) ballot version was created.

8. Each chapter was balloted by TAC with resolution of all comments by both TAC and the Industry Handbook Committee.

133PCI Journal | Fal l 2010

the prestressed concrete industry in the United States. For additional information related to the history of the industry, refer to Reflections on the Beginnings of Prestressed Con-crete in America,9 published in 1981, and PCI Visions Taking Shape,10 published in 2004. These documents commemorate the 25th and 50th anniversaries of PCI, respectively.

The sixth-edition figure of typical products has been re-placed with a collage of photographs to better illustrate the variety of products available (Fig. 2).

Because of the growing emphasis on sustainability, section 1.1.3, “Sustainability and LEED Considerations,” has been added to describe the benefits of precast and prestressed concrete in achieving long-lasting and energy-efficient structures.

A new section 1.2.1.7, Educational Facilities, has been added to better illustrate the importance of these applica-tions and to present to the user of the handbook the supe-rior solutions that precast and prestressed concrete offers to the owners of these facilities.

The sixth-edition section 1.3, Materials, was completely removed from chapter 1. It was extensively expanded and has become the new chapter 9 of the PCI Design Hand-book, seventh edition. See the discussion in this article on chapter 9 for further details of the changes and additions on the subject of materials.

Chapter 2—Notations

This chapter is completely new and includes the notations for the entire handbook. This is the result of the PCI Indus-try Handbook Committee’s intention to make the handbook similar to ACI 318-05. It was the original intention to include definitions in this chapter, but the committee con-sidered it more user friendly to include definitions either at the beginning of 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 identified with “(ACI)” after the definition.

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 provi-sions. Load capacities have not changed significantly, except for short-span components where reduced phi fac-tors 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

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.

Chapter 4—Analysis and Design of Precast/Prestressed Concrete Structures


The chapter on the analysis and design of precast and pre-stressed concrete structural systems has been updated to re-flect the requirements of ACI 318-05, IBC 2006, and ASCE 7-05. There has been an update of the discussion on precast concrete lateral systems, which reflects the more-severe treatment in ASCE 7-05 of cantilevered column systems.

The ASCE 7-05 update for seismic systems includes an alternate equation for the determination of the approximate building period for shear-wall structures. The change to the requirements and factors for redundancy for high-seismic design categories is discussed. The discussion of recom-mended loads for diaphragm design has been updated in an effort to clarify the difference between a diaphragm over-strength factor Ψ and the system overstrength factor Ω0.

The new, more prescriptive requirement for a positive horizontal connection force parallel to supported compo-nents in ASCE 7-05 section 12.1.4 is discussed as part of updated information on structural integrity.

Some advanced results from the PCI-sponsored volume-change study have also been included.11

The design examples for moment-resisting frames are cov-ered in more detail in the PCI Seismic Design Manual,12 pub-lished in 2007, and are no longer repeated in the handbook.

Figure 1. Walnut Lane Memorial Bridge.


ba

c

e f

hg i

d

Figure 2. Typical products of the industry.


Examples for shear-wall buildings and for precast concrete diaphragms have been updated to clarify diaphragm and collector design procedures. Diaphragm design has been expanded, and more detail is provided for collectors.

Figures 3 and 4 illustrate the intent of ASCE 7-05 and IBC 2006.

An entirely new section (section 4.9) on blast-resistant design has been added to the chapter. This section dis-cusses the special considerations of large-magnitude,

Figure 4. Perspective view of shear wall and collectors.

Shear wall

Connection to shear wall

Collector reinforcement in topping

Collector reinforcementin line with shear wall

Cast-in-placetopping

Double-teedeck

Figure 3. Collector force demand diagram for shear walls in a parking garage. See note a in Postpublication Notes at the end of this article.

• •

bays at

typical

Ramp downShear wallsRamp up

typi

cal

Stairwell

Elevator

bays

at

Collector force demand


the original research, use of the effective coefficient 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

short-duration loads on precast concrete systems with large mass and inertia. Topics include blast loads, dynamic mate-rial properties, and blast-design methods. A blast-design example for a cladding panel is also included.

Chapter 5—Design of Precast and Prestressed Concrete Components


Section 5.2.3 and example 5.2.3.2 have been revised to al-low for the use of an interpolated phi factor φ for under-developed strand in accordance with ACI 318-05 section 12.9.1. This section and the example show that for the flex-ural 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 significantly expanded to increase design guidelines and provide a complete design example for stadium-seating components.

Based on a review of the original research,13 section 5.3.6 has been revised to correct the equation for the effective shear friction coefficient (Eq. [5-33]) to include the phi factor φ in the numerator. Also, based on this review of

Table 2. Recommended shear-friction coefficients (6th edition)

Crack interface condition Recommended µ Maximum µe Maximum Vu = φVn

1. Concrete to concrete, cast monolithically

1.4λ 3.4 0.30λ2f 'c Acr ≤ 1000λ2Acr

2. Concrete to hardened concrete, with roughened surface

1.0λ 2.9 0.25λ2f 'c Acr ≤ 1000λ2Acr

3. Concrete to concrete 0.6λ 2.2 0.20λ2f 'c Acr ≤ 800λ2Acr

4. Concrete to steel 0.7λ 2.4 0.20λ2f 'c Acr ≤ 1000λ2Acr

Table 3. Recommended shear-friction coefficients (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

2Concrete to hardened concrete, with roughened surface

1.0λ 2.9 0.25λf 'c Acr ≤ 1000λAcr

3Concrete placed against hardened concrete not intentionally roughened

0.6λ Not applicableb 0.20λf 'c Acr ≤ 800λAcr

4 Concrete to steel 0.7λ Not applicableb c0.20λf 'c Acr ≤ 1000λAcr

a. In accordance with ACI 318-05 Section 11.7.4.3.b. The use of µe is not applicable for concrete placed against hardened concrete not intentionally roughened or against steel.c. The handbook shows this as 0.30λf 'c Acr ≤ 1000λAcr. This is incorrect. It should be 0.20λf 'c Acr ≤ 1000λAcr.


Chapter 6—Design of Connections

Section 6.2.3 has been added to differentiate IBC 2006 requirements from recommended PCI values for seismic overstrength factors for lateral-force-resisting systems.

Tables 4 and 5 (Tables 6.2.1 and 6.2.2 in the seventh-edition PCI Design Handbook) have been added to clarify overstrength factors applicable for diaphragms and collec-tor systems, respectively.

Section 6.4.3.1, Reinforcing Bars in Conduit, has added requirements for supplemental reinforcement based on the previous research.18

Table 6.5.5, Summary table of HCA (headed concrete anchors) group concrete shear strength equations, has been added to conveniently show the appropriate design factor for each failure mode.

Design Example 6.5.5.4, Design of Bearing Seat with Headed Concrete Anchors (Example 6.5.8.1 in the sixth edition), has been modified to include the weld require-ments for the bearing seat, and a table has been added that shows all of the component design strengths.

Further explanation of the interaction of tension and shear for headed concrete anchors has been added to section 6.5.8, Interaction of Tension and Shear.

Examples 6.6.5.1(a) and 6.6.5.1(b) are new and illustrate the design procedure for an unstiffened connection angle using headed concrete anchors and bolts, respectively.

Section 6.7.2.1, Fillet Welds, has been modified to more accurately represent the nominal design strength of a fillet weld element. This section now includes the effect of the angle of loading with respect to the axis of the weld ele-ment.

Enhancement has been added to the Instantaneous Center Method (ICM) for weld design in section 6.7.5.2 to more clearly demonstrate the design approach.

Chapter 5 modified the calculation of effective shear fric-tion, and this revision has been applied to the chapter 6 design examples, where appropriate.

Cazaly Hanger, section 6.9.1, has been modified to reflect recent research indicating that previous editions may not have been adequately conservative. While the procedure is essentially the same, an additional requirement for anchor reinforcement has been introduced to avoid a concrete breakout failure (Fig. 5). This is illustrated below.

Concerns raised by PCI Professional Members suggested the need for better clarity of the detailing requirements for dap-ended members. Accordingly, the committee modified Fig. 5.6.3 by enlarging the alternative dap reinforcement detail to clarify and emphasize the importance of dap rein-forcement detailing and placement.

Section 5.8, Camber and Deflection, was expanded, pri-marily to provide guidance for the use of ACI 318-05 Table 9.5(b) Maximum Permissible Computed Deflections (PCI Design Handbook Table 5.8.1).

Section 5.9, Compression Components, contains several significant revisions. In section 5.9.1, the section allow-ing elimination of lateral ties in certain instances based on Recommended Practice for the Design of Prestressed Concrete Columns and Walls15 has been removed because the reference no longer contains these exceptions.

In Example 5.9.1.1, the interaction curve has been modi-fied 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 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.

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.

Section 5.11, Sandwich Panels, was moved into this chap-ter 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 5.12.1, Point Loads on Double-Tee Flanges, is a new section, though the design example was in the Analy-sis 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 reflect load test data.16

Section 5.12.7, Warping of Deck Components, is a com-pletely new section. It addresses the warping of double-tees, especially in parking structures, to obtain desired drainage patterns. Recommendations are based on experi-ence 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 flexure, shear, or maximum Vu.


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 Com-bined Loading, is new and illustrates a combined shear and tension connection and the interaction equations for each component and the capacity region of the assembly.

Example 6.13.8, Deformed Bar or Reinforcing Bar Con-nection Plate Supporting Steel Beam, is new and illustrates a typical connection for a steel, wide-flange beam con-nected to a plate with deformed bar anchors. See note c in Postpublication Notes at the end of this article.

Design Aids 6.15.4 and 6.15.5 no longer show weld size and minimum plate thickness requirements for welds us-ing E70 electrodes for ASTM Grade 60 reinforcing bars because this is no longer allowed by AWS D1.4.19

Chapter 6 DESIGN OF CONNECTIONS

6–60

6

PCI DESIGN HaNDbOOk/SEvENTH EDITION

Design of the bar or HSS is then accomplished so that:

The size of the bar must be such that for combined flexure and tension the actual stress ≤ 0.9Fy

For flexure:

Zrequired = Mu /φFy = [Vu(φlp + g + c + 0.5Sw)+ Nu (0.5)Y]/φFy (Eq. 6-81)

Then based on a trial section check that the actual stress due to combined flexure and tension is ≤ 0.9Fy

For shear: Actual shear stress is ≤ 0.9(0.6Fy)

4. Provide anchor reinforcement distributed uniformly over 0.8d as illustrated in Fig. 6.9.2(b) to resist 1.33 Vu.

Av Au =1.33Vu

φ fy (Eq. 6-82)

Check minimum area required: where:

Aν= 0.75 fc

'bws

fy

not less than 50bws

fy (Eq. 5-24)

bw = width of component (see Fig. 6.9.2(b))

s = 0.8d

5. The conservative and simplifying assumption that strap weld forces are concentrated at the strap center-line is implicit in the 0.5Sw factor in the value of a in Eq. 6-80.

6. The bearing pressure creating the interior reaction may be calculated as in Section 5.6.1. Conservatively, if the width of the component in which the hanger is cast equals bw, then:

fbu = 0.85φ fc'

bw

b≤1.1 fc

' (Eq. 6-83)

where:φ = 0.65

The bearing length lb is then given by:

b =

Vu

3bfbu

(Eq. 6-84)

7. To maintain the conditions of equilibrium assumed, the interior cantilever must have a length:

3a = 1.5lp + 3.0g + 3.0c + 1.5Sw

8. The minimum total length of bar is then:

l = 0.5lp + a + 3.0a +0.5lb

= 2.5lp + 4.0g + 4.0c + 2.0Sw +0.5lb (Eq. 6-85)

6.9 Hanger Connections

Hangers are similar to dapped ends, except that the extended or bearing end is steel instead of concrete. They are used when it is desired to keep the structural depth very shallow. Exam-ples are shown in Fig. 6.9.1. These connections typically have short bearings and may be particularly sensitive to tolerances and volume-change movements. The need for accuracy in dimensioning and installation must be emphasized.

6.9.1 Cazaly Hanger22

The Cazaly hanger has three basic components (Fig.6.9.2[a]). Design assumptions are as follows (Fig. 6.9.2[b]):

1. The cantilevered bar is usually proportioned so that the interior reaction from the concrete is 0.33Vu. The hanger strap should then be proportioned to yield under a tension of 1.33Vu:

As =1.33Vu

φFy

(Eq. 6-79)

where:Fy = yield strength of strap materialφ = 0.90

The hanger strap must terminate at or below the flex-ural reinforcing to avoid a breakout failure plane start-ing in the splitting tension zone. Cover requirements must be satisfied.

2. Vu may be assumed to be applied lp/2 from the face of the seat. The remaining part of the moment arm is the width of the joint g and the cover c from the end of the component to the edge of the strap. Since moment is sensitive to this dimension, it is important that this dimension be kept as small as possible and that the value used in analysis is not exceeded in the erected structure. Most hangers in practice have exterior can-tilever lengths, (lp + g + c), of 4 in. to 6 in.

3. The bar should be proportioned to carry the moment in combination with shear and tensile forces.

The moment in the cantilevered bar is made up of bend-ing due to the vertical force Vu with an eccentricity = a, and Nu with and eccentricity = 0.5Y and is given by:

Mu = Vu a + Nu(0.5)Y Eq. 6-80

where:a = 0.5lp + g + c + 0.5Sw

lp = bearing length at the supportY = depth of the bar or hollow structural sec-

tion (HSS)

Other notation is shown in Fig. 6.9.2(b).

It may be prudent to use a slightly higher value for “a” to account for fabrication and erection tolerances and the sensitivity of the connection. This is at the engi-neer’s judgment.

Table 4. Diaphragm overstrength factorsa

Ψ factor table design element Seismic design category

A B C D E F

Diaphragm to SFRS connection

Bearing-wall systems 1 1 2.5a 2.5a 2.5a 2.5a

Building-frame systems 1 1 2.5a 2.5a 2.5a 2.5a

Moment-resisting systems 1 1 2.5a 3a 3a 3a

Dual system with special moment frames 1 1 2.5a 2.5a 2.5a 2.5a

Dual system with intermediate moment frames 1 1 2.5a 2.5a 2.5a 2.5a

Inverted pendulum system and cantilevered-column systems 1 1 2.5a 2 2 2

Diaphragm chord element

Bearing-wall systems 1 1 1b 2 2 2

Building-frame 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 joint shear connection

Bearing-wall systems 1 1 1b 2 2 2

Building-frame 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

a. The tabulated value of the diaphragm overstrength factor Ψ may be reduced by subtracting 0.5 for structures with flexible diaphragms but shall not be taken as less than 2.0 for any structure.

b. For seismic design category C diaphragms, it has been assumed that the maximum distributed design force at that level is used.


Table 5. Seismic overstrength factorsa

Ωo factor table design element Seismic design category

A B Cb Db Eb Fb

Collectors (drag-ties)

Bearing-wall systems 1 1 2.5 2.5 2.5 2.5

Building-frame 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 frames 1 1 2.5 2.5 2.5 2.5

Dual system with intermediate moment frames 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-tie) transfer to vertical resisting element

Bearing-wall systems 1 1 2.5 2.5 2.5 2.5

Building-frame 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 frames 1 1 2.5 2.5 2.5 2.5

Dual system with intermediate moment frames 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

a. Table shown is condensed from ASCE 7-05, Table 12.2-1.

b. The tabulated value of the system overstrength factor Ωo may be reduced by subtracting 0.5 for structures with flexible diaphragms but shall not be taken as less than 2.0 for any structure.

Figure 5. Cazaly hanger.

Y

1/2p

1/2b

d

dp

b

Supportg

c Outline ofcomponent

MainreinforcementStrap, Sw

Nu

Vu

An

bw

b

d h

a 3a

s = 0.8d

Av

Avf

Nu

Cantilever bar or HSS

Steelhangerstrap

Dowels

(a) (b)


Chapter 7—Structural Considerations for Architectural Precast Concrete

This chapter is very much like its counterpart in the sixth edition, with several noteworthy additions:

• It includes material from the third edition of PCI’s Architectural Precast Concrete,20 published in 2007, that is particularly important for 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 different 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 of Example 4.2.3.1, which uses ASCE 7-05 to calculate wind loads on a building to design for 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 of 60 ft (18 m) and many architectural cladding components are used on taller buildings.

— Example 7.5.3.1, Architectural Precast Con-crete Panel with Earthquake Loading. This example is the same as Example 3.2.4.2 in the sixth edition, but has been expanded to reflect ap-propriate seismic factors. It includes comparisons of critical loads from the two previous wind-load examples to illustrate the actual design procedure that an engineer would use.

• Seismic drift considerations have been added to il-lustrate the need for some connections to move in different directions to avoid unintended forces acting on the cladding and/or the supporting structure. This is illustrated in Fig. 6.

• The chapter has added recommendations for 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 for the design of spreader beams used in handling precast concrete components.

Section 8.6, Erection Handling, has been revised to ad-dress uncontrolled rolling when erecting wall panels with three-point pick using rolling blocks between the two bottom lifting points. Some erectors and engineers have

Figure 6. Cladding panel connection concepts—seismic drift effect (translating panels).

(a) Wall panels

Deflectedposition of grid

(b) Spandrel panels

Columnlines

Floor level

Floor level

Seismic reactions

Note: Gravity and out-of-planeloads to connectors not shown; C.G. = center of gravity

Bearing connectionTie-back connectionAllowed movement direction

Spandrel panel

Seismicforce

C.G.

Spandrel panelin translated position

C.G.

Seismicreaction Seismic reactions

Seismic force

Window


observed firsthand that the equation shown in Fig. 5.6.2 of the sixth edition for the distance from the lower rolling block to the center of 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 Indus-try Handbook Committee has recommended the rigging arrangement illustrated in Fig. 9 to avoid this condition.

Section 8.7, Erection Bracing, was reduced to an abbrevi-ated version, and design examples were removed. This was a topic that was debated significantly by the Industry Hand-book Committee, primarily as a result of the difference between the experiences of the committee members and the requirements of ASCE 37-02 Design Loads on Struc-tures 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 of the experienced precast concrete designer. With that responsibility must go the authority to define the loading requirements during this temporary stage.

Chapter 9—Precast and Prestressed Concrete: Materials

Chapter 9 is a new chapter dealing exclusively with materi-als affecting and used in precast and prestressed concrete construction. Chapter 9 represents a consolidation of several material sections that were contained in various chapters of past handbook editions. Major topics include concrete, grouts, connection materials, corrosion protec-

tion, reinforcement, waterproofing, and in-service repairs. The chapter also includes a number of new figures, graphs, and tables to augment the text.

Because the handbook is often used as a textbook at the university level and many students have not been exposed to typical materials used in the industry, several photo-graphs have been included—for example, prestressing strand (Fig. 10) and standard reinforcement (Fig. 11).

Section 9.2, Concrete, covers the constituent materials of the concrete matrix, consisting of cement, supplementary cementitious materials (SCMs), aggregates, admixtures, and pigments. Detailed descriptions are provided with relevant references to ASTM standards. Physical properties of concrete are introduced, such as compressive and tensile strength, modulus of elasticity, volume changes, and durability. Tables presenting common material parameters are given and photographs of good concrete and common deterioration mechanisms are presented, as illustrated in Fig. 12 and 13, respectively.

Figure 7. Typical cladding connection locations.

(a) Wall panel

Column cover options(b) (c)

(d) Spandrel panel

Optionalfor long panels

Bearing connectionTieback connection

Figure 8. Stability during erection.

e >

2

2 − b2

2− a

Figure 9. Stability during erection.

Center of gravity

W


viding protection against deterioration are covered within the context of waterproofing with coatings, joint sealant types and issues, and expansion joint sealant systems.

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 Stan-dards and Publications, which is a comprehensive listing of reference standards and publications relevant to materi-als. These standards may also appear in project specifica-tions prepared by the engineer of record or architect of record.

Chapter 10—Design for Fire Resistance of Precast and Prestressed Concrete

This was section 9.3 in the sixth edition and is now a standalone chapter to emphasize the many benefits of pre-cast concrete in fire protection.

Section 10.6.2, Continuous Components (section 9.3.7.2, Continuous Members, in the sixth edition), has been short-ened by eliminating other loading conditions beyond the two-span case discussed. Refer to PCI MNL-124-8923 for additional load case discussion.

Example 9.3.7.1, Fire Endurance for Hollow-Core Slab with Topping, from the sixth edition has been eliminated because most applications for residential use do not use topping and still satisfy fire-endurance requirements.

Example 10.8.1, Fire Endurance by Code Tables, for a double-tee with topping, has been updated to reflect IBC 2006.

Section 9.4, Connection Materials, reviews the common steel sections, bearing pads, and bolts used in connections. This is followed by a discussion on the galvanic series and its importance in examining service life and protection of connections. Protection means are discussed, including painted systems, galvanized steel, and stainless steel, and the proper means of specifying them.

Section 9.6, Reinforcement, describes various systems for precast and prestressed concrete components and the various deterioration mechanisms that can occur. Different means of embedded steel protection are presented to miti-gate common deterioration problems. Other means of pro-

Figure 12. Example of good air-void system.

Figure 13. Planar cracking marking freezing and thawing damage.

Figure 11. Reinforcing bars of various sizes, from no. 18 to no. 3.

Figure 10. Wire prestressing strand of various sizes.


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 of vibra-tion control in certain types of facilities. There are no sig-nificant changes; however, a minor change is the addition of 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 of the PCI Design Handbook. The only other changes are editorial and correction of some minor errors.

Chapter 14—Specifications and Standard Practices


The most significant change from the previous edition was the reorganization of the sections. PCI Standard Design Practice (section 14.1) has been placed first because it is believed to be the most important information for the

A new section 10.8, Requirements for Parking Structures, has been added to assist the user in applying the require-ments and tables in IBC 2006 to the design of 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 performed to evaluate realistic vehicle-fire loads (time-temperature or time-heat flux relationships) for precast concrete parking structures. This work investigated the influence of the structural geometry and fire character-istics on the resulting fire load.

Chapter 11—Thermal and Acoustical Properties of Precast Concrete

The topics of chapter 11 comprise sections 9.1 and 9.2 from the sixth edition. The chapter provides updated infor-mation on both topics, as well as adding design guidelines for calculating the thermal resistance of sandwich panels using metal ties between concrete wythes.

Figure 14. Natural frequency of selected floor units.

Nat

ura

l fre

qu

ency

fn, H

z

12DT30

f ’c = 5000 psi, normalweightEd = 1.2 × 33 × 1501.5 × f ’c

With 10 lb/ft superimposed load

Span, ft

2

1

5

7

9

11

12

10

Use of values below 3 Hz is not recommended

12DT28+2

10DT32+2

15DT34

8DT24+2

4HC8+2

4HC12+2

FS6+2


Appendix—Impact of ACI 318-08 on this Handbook

The appendix is totally new and is the result of PCI’s TAC directing that the impact of ACI 318-0827 be included in the seventh edition. It is based entirely on four papers written by S. K. Ghosh and published as a supplement to separate issues of the PCI Journal.28–31 The PCI Industry Handbook Commit-tee reviewed those papers and included in the appendix those portions that have an impact on sections of the handbook.

Conclusion

Most of the goals established by the PCI Industry Hand-book Committee for the seventh edition have been accom-plished. However, several were not and will remain goals for the eighth edition, as noted in the following paragraphs.

Chapter 2, Notations, was intended to include definitions used throughout the handbook, as well as other terms typically used in the industry that might not be specifically used in the handbook. Terms such as down-in-form, chuck, stripping, dunnage, and the like are used in everyday conversation in plants and may be helpful for the inexperi-enced designer or student using the handbook.

A review of chapter 2 also resulted in the observation that the notation used in the handbook could be improved with a complete overhaul. Many of the same notations have different meanings, which can cause confusion. Examples include the notation R, which is the response modification factor for seismic design in chapter 4 and the thermal resis-tance of a precast concrete component in chapter 11.

There are numerous less-critical topics and suggested changes brought forward for consideration, but the deci-sion to incorporate them was postponed because of timing and publishing constraints. Similar thoughts occurred during the blue-ribbon review. The committee has gath-ered these items for future consideration and has provided them to the next PCI Industry Handbook Committee, to be chaired by Tim Salmons, P.E., S.E. The list of items for the eighth edition of the PCI Industry Handbook Committee to address also includes:

• 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 ver-sions of ACI 318, IBC, and ASCE will be used for the eighth edition.

• Consider making the publication a two-volume set, with one including material that does not necessarily change with the code cycles.

• Use 3 in. (75 mm) topping for double-tee load tables instead of 2 in. (50 mm).

designer in the chapter. It has been updated to reflect ACI 318-05 and has had extensive review by the PCI Building Code Committee and TAC.

Sections 14.2 and 14.3 are brief descriptions of the guide specifications for structural and architectural precast concrete, respectively. They have both been updated to the latest ACI 301 and AIA Masterspec.24,25 The full guide specifications are on the CD in the front jacket pocket of the PCI Design Handbook and are in a usable word-pro-cessing format.

Section 14.4, Standard Operations Practice Recommen-dations for Precast Concrete, has been updated to reflect current practices in the industry.

Section 14.5, Recommendations on Responsibility for Design and Construction of Precast Concrete Structures, remains essentially the same as in the sixth edition.

Chapter 15—General Design Information


The following is a listing of the most significant changes in this chapter:

• All Design Aids have been reorganized to better reflect the topic.

• All Design Aids have been updated to reference the current model codes and standards. Numerical values have been modified where required. For example, the uniform floor loading in passenger-car parking struc-tures was revised from 50 lb/ft2 (244 kg/m2) to 40 lb/ft2

(195 kg/m2).

• The sixth-edition Design Aid 11.2.1 has been omitted from the seventh edition because it is easy to calculate the values that are a function of 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 equa-tions for the modulus of elasticity of concrete.

• The new seventh-edition Design Aid 15.4.2 has been added and includes typical bent reinforcing bar configurations and designations. The source for this information is ACI’s publication Details and Detailing of Concrete Reinforcement.26

• The new seventh-edition Design Aid 15.5.4 has been added and illustrates common styles of welded-wire reinforcement (WWR) shear reinforcement used in the ends of double-tee stems.


3. PCI Plant Certification Committee. 1999. Manual for Quality Control for Plants and Production of Struc-tural Precast Concrete Products. MNL-116-99. 4th ed. Chicago, IL: PCI.

4. PCI Architectural Precast Concrete Services Commit-tee and Plant Certification Committee. 1996. Manual for Quality Control for Plants and Production of Ar-chitectural Precast Concrete Products. MNL-117-96. 3rd ed. Chicago, IL: PCI.

5. PCI Glass Fiber Reinforced Concrete Panels Com-mittee. 2009. Manual for Quality Control for Plants and Production of Glass-Fiber Reinforced Concrete Products. MNL-130-09. Chicago, IL: PCI.

6. American Society of Civil Engineers (ASCE). 2005. Minimum Design Loads for Buildings and Other Structures. Structural Engineering Institute (SEI)/ASCE 7-05 and Supplement No. 2. Reston, VA: ASCE.

7. International Code Council. 2006. International Build-ing 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. Reflections on the Beginnings of Pre-stressed Concrete in America. Chicago, IL: PCI.

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 of Precast/Prestressed Concrete Structures. MNL-140-07. Chicago, IL: PCI.

13. Mattock, A. H., W. K. Li, and T. C. Wang. 1976. Shear Transfer in Lightweight Reinforced Concrete. PCI Journal, V. 32, No. 1 (January–February): pp. 20–39.

14. Klein, G. J. 1986. Design of Spandrel Beams. PC-ISFRAD project no. 5. PCI Journal, V. 31, No. 5 (September–October): pp.76–124.

15. PCI Committee on Prestressed Concrete Columns. 1988. Recommended Practice for the Design of Pre-stressed Concrete Columns and Walls. PCI Journal, V. 33, No. 4 (July–August): pp. 56–75.

16. Aswad, Alex, and George Burnley. 1991. Point Load

• Reintroduce material related to erection bracing and include examples.

• Create a uniform format for all examples and all figures.

• Consider providing a final draft of the eighth edition to the entire engineering community for public com-ment. While the seventh edition has had a very intense review process, it cannot be considered a consensus document. Responding to public comments would al-low the document to achieve this status.

• Update the handbook to reflect ongoing research.

As stated in the foreword, the PCI Design Handbook is a living document. Comments related to any aspect of 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 therefore intends to publish errata based on input of the users of 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 of Technical Activities at PCI, Jason Krohn, 200 West Adams Street, Suite 2100, Chicago, IL 60606.

Postpublication Notes

After publication of the handbook, several errata that affect this article were observed as follows. These and other er-rata will be published in a future issue of the PCI Journal.

a. Figure 4.8.4 of the seventh edition is not correct in that the horizontal line just above the lower shear wall on the right side of the plan should line up with the end of that shear wall. Figure 3 in this article is correct.

b. Example 5.2.3.2 does not correctly reflect the text of the seventh edition in that it does not properly account for load in the partially developed strands.

c. Use of E70 electrodes has been a common practice in the industry for years. The statement that this is no longer allowed by AWS D1.4 is incorrect. Refer to the sixth-edition PCI Design Handbook, which is correct.

References

1. PCI Industry Handbook Committee. 2010. PCI Design Handbook: Precast and Prestressed Concrete. MNL-120-10. 7th ed. Chicago, IL: PCI.

2. American Concrete Institute (ACI) Committee 318. 2005. Building Code Requirements for Structural Con-crete (ACI 318-05) and Commentary (ACI 318R-05). Farmington Hills, MI: ACI.


31. Ghosh, S. K. 2009. Significant Changes to ACI 318-08 Relative to Precast/Prestressed Concrete: Part 4. PCI Journal. Suppl. no. 54-3.

Tests of 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 of 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—Reinforcing 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 of Civil Engineers (ASCE)/Struc-tural Engineering Institute (SEI). 2002. Design Loads on Structures During Construction. SEI/ASCE 37-02. Reston, VA: ASCE.

23. PCI Fire Committee. 1989. Design for Fire Resistance of Precast Prestressed Concrete. MNL-124-89. 2nd ed. Chicago, IL: PCI.

24. American Institute of Architects. 2006. Masterspec 2004. Salt Lake City, UT: ARCOM.

25. ACI Committee 301. 2010. Specifications for Struc-tural Concrete. Farmington Hills, MI: ACI.

26. ACI. 1999. Details and Detailing of Concrete Rein-forcement. ACI 315-99. Farmington Hills, MI: ACI.

27. ACI Committee 318. 2008. Building Code Require-ments for Structural Concrete (ACI 318-08) and Com-mentary (ACI 318R-08). Farmington Hills, MI: ACI.




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