Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page R1
NATIONAL
NCHRP REPORT 679
COOPERATIVE
HIGHWAY
RESEARCH
PROGRAM
Design of Concrete Structures
Using High-Strength
Steel Reinforcement
OCR for page R2
TRANSPORTATION RESEARCH BOARD 2011 EXECUTIVE COMMITTEE*
OFFICERS
CHAIR: Neil J. Pedersen, Administrator, Maryland State Highway Administration, Baltimore
VICE CHAIR: Sandra Rosenbloom, Professor of Planning, University of Arizona, Tucson
EXECUTIVE DIRECTOR: Robert E. Skinner, Jr., Transportation Research Board
MEMBERS
J. Barry Barker, Executive Director, Transit Authority of River City, Louisville, KY
Deborah H. Butler, Executive Vice President, Planning, and CIO, Norfolk Southern Corporation, Norfolk, VA
William A.V. Clark, Professor, Department of Geography, University of California, Los Angeles
Eugene A. Conti, Jr., Secretary of Transportation, North Carolina DOT, Raleigh
James M. Crites, Executive Vice President of Operations, Dallas-Fort Worth International Airport, TX
Paula J. Hammond, Secretary, Washington State DOT, Olympia
Adib K. Kanafani, Cahill Professor of Civil Engineering, University of California, Berkeley
Susan Martinovich, Director, Nevada DOT, Carson City
Michael R. Morris, Director of Transportation, North Central Texas Council of Governments, Arlington
Tracy L. Rosser, Vice President, Regional General Manager, Wal-Mart Stores, Inc., Mandeville, LA
Steven T. Scalzo, Chief Operating Officer, Marine Resources Group, Seattle, WA
Henry G. (Gerry) Schwartz, Jr., Chairman (retired), Jacobs/Sverdrup Civil, Inc., St. Louis, MO
Beverly A. Scott, General Manager and CEO, Metropolitan Atlanta Rapid Transit Authority, Atlanta, GA
David Seltzer, Principal, Mercator Advisors LLC, Philadelphia, PA
Lawrence A. Selzer, President and CEO, The Conservation Fund, Arlington, VA
Kumares C. Sinha, Olson Distinguished Professor of Civil Engineering, Purdue University, West Lafayette, IN
Daniel Sperling, Professor of Civil Engineering and Environmental Science and Policy; Director, Institute of Transportation Studies; and Interim
Director, Energy Efficiency Center, University of California, Davis
Kirk T. Steudle, Director, Michigan DOT, Lansing
Douglas W. Stotlar, President and CEO, Con-Way, Inc., Ann Arbor, MI
C. Michael Walton, Ernest H. Cockrell Centennial Chair in Engineering, University of Texas, Austin
EX OFFICIO MEMBERS
Peter H. Appel, Administrator, Research and Innovative Technology Administration, U.S.DOT
J. Randolph Babbitt, Administrator, Federal Aviation Administration, U.S.DOT
Rebecca M. Brewster, President and COO, American Transportation Research Institute, Smyrna, GA
Anne S. Ferro, Administrator, Federal Motor Carrier Safety Administration, U.S.DOT
John T. Gray, Senior Vice President, Policy and Economics, Association of American Railroads, Washington, DC
John C. Horsley, Executive Director, American Association of State Highway and Transportation Officials, Washington, DC
David T. Matsuda, Deputy Administrator, Maritime Administration, U.S.DOT
Victor M. Mendez, Administrator, Federal Highway Administration, U.S.DOT
William W. Millar, President, American Public Transportation Association, Washington, DC
Tara O'Toole, Under Secretary for Science and Technology, U.S. Department of Homeland Security, Washington, DC
Robert J. Papp (Adm., U.S. Coast Guard), Commandant, U.S. Coast Guard, U.S. Department of Homeland Security, Washington, DC
Cynthia L. Quarterman, Administrator, Pipeline and Hazardous Materials Safety Administration, U.S.DOT
Peter M. Rogoff, Administrator, Federal Transit Administration, U.S.DOT
David L. Strickland, Administrator, National Highway Traffic Safety Administration, U.S.DOT
Joseph C. Szabo, Administrator, Federal Railroad Administration, U.S.DOT
Polly Trottenberg, Assistant Secretary for Transportation Policy, U.S.DOT
Robert L. Van Antwerp (Lt. Gen., U.S. Army), Chief of Engineers and Commanding General, U.S. Army Corps of Engineers, Washington, DC
Barry R. Wallerstein, Executive Officer, South Coast Air Quality Management District, Diamond Bar, CA
*Membership as of March 2011.
OCR for page R3
NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM
NCHRP REPORT 679
Design of Concrete Structures
Using High-Strength
Steel Reinforcement
Bahram M. Shahrooz
Richard A. Miller
UNIVERSITY OF CINCINNATI
Cincinnati, OH
Kent A. Harries
UNIVERSITY OF PITTSBURGH
Pittsburgh, PA
Henry G. Russell
HENRY G. RUSSELL, INC.
Glenview, IL
Subscriber Categories
Highways · Bridges and Other Structures
Research sponsored by the American Association of State Highway and Transportation Officials
in cooperation with the Federal Highway Administration
TRANSPORTATION RESEARCH BOARD
WASHINGTON, D.C.
2011
www.TRB.org
OCR for page R4
NATIONAL COOPERATIVE HIGHWAY NCHRP REPORT 679
RESEARCH PROGRAM
Systematic, well-designed research provides the most effective Project 12-77
approach to the solution of many problems facing highway ISSN 0077-5614
administrators and engineers. Often, highway problems are of local ISBN 978-0-309-15541-0
interest and can best be studied by highway departments individually Library of Congress Control Number 2011921824
or in cooperation with their state universities and others. However, the © 2011 National Academy of Sciences. All rights reserved.
accelerating growth of highway transportation develops increasingly
complex problems of wide interest to highway authorities. These
problems are best studied through a coordinated program of COPYRIGHT INFORMATION
cooperative research.
Authors herein are responsible for the authenticity of their materials and for obtaining
In recognition of these needs, the highway administrators of the written permissions from publishers or persons who own the copyright to any previously
American Association of State Highway and Transportation Officials published or copyrighted material used herein.
initiated in 1962 an objective national highway research program Cooperative Research Programs (CRP) grants permission to reproduce material in this
employing modern scientific techniques. This program is supported on publication for classroom and not-for-profit purposes. Permission is given with the
understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA,
a continuing basis by funds from participating member states of the
FMCSA, FTA, or Transit Development Corporation endorsement of a particular product,
Association and it receives the full cooperation and support of the method, or practice. It is expected that those reproducing the material in this document for
Federal Highway Administration, United States Department of educational and not-for-profit uses will give appropriate acknowledgment of the source of
any reprinted or reproduced material. For other uses of the material, request permission
Transportation.
from CRP.
The Transportation Research Board of the National Academies was
requested by the Association to administer the research program
because of the Board's recognized objectivity and understanding of
NOTICE
modern research practices. The Board is uniquely suited for this
purpose as it maintains an extensive committee structure from which The project that is the subject of this report was a part of the National Cooperative Highway
Research Program, conducted by the Transportation Research Board with the approval of
authorities on any highway transportation subject may be drawn; it the Governing Board of the National Research Council.
possesses avenues of communications and cooperation with federal,
The members of the technical panel selected to monitor this project and to review this
state and local governmental agencies, universities, and industry; its report were chosen for their special competencies and with regard for appropriate balance.
relationship to the National Research Council is an insurance of The report was reviewed by the technical panel and accepted for publication according to
procedures established and overseen by the Transportation Research Board and approved
objectivity; it maintains a full-time research correlation staff of
by the Governing Board of the National Research Council.
specialists in highway transportation matters to bring the findings of
The opinions and conclusions expressed or implied in this report are those of the
research directly to those who are in a position to use them. researchers who performed the research and are not necessarily those of the Transportation
The program is developed on the basis of research needs identified Research Board, the National Research Council, or the program sponsors.
by chief administrators of the highway and transportation departments The Transportation Research Board of the National Academies, the National Research
and by committees of AASHTO. Each year, specific areas of research Council, and the sponsors of the National Cooperative Highway Research Program do not
needs to be included in the program are proposed to the National endorse products or manufacturers. Trade or manufacturers' names appear herein solely
because they are considered essential to the object of the report.
Research Council and the Board by the American Association of State
Highway and Transportation Officials. Research projects to fulfill these
needs are defined by the Board, and qualified research agencies are
selected from those that have submitted proposals. Administration and
surveillance of research contracts are the responsibilities of the National
Research Council and the Transportation Research Board.
The needs for highway research are many, and the National
Cooperative Highway Research Program can make significant
contributions to the solution of highway transportation problems of
mutual concern to many responsible groups. The program, however, is
intended to complement rather than to substitute for or duplicate other
highway research programs.
Published reports of the
NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM
are available from:
Transportation Research Board
Business Office
500 Fifth Street, NW
Washington, DC 20001
and can be ordered through the Internet at:
http://www.national-academies.org/trb/bookstore
Printed in the United States of America
OCR for page R5
The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific
and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. On the
authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal
government on scientific and technical matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences.
The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel
organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the
National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also
sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior
achievements of engineers. Dr. Charles M. Vest is president of the National Academy of Engineering.
The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members
of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the
responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government
and, on its own initiative, to identify issues of medical care, research, and education. Dr. Harvey V. Fineberg is president of the
Institute of Medicine.
The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of
science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in
accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the
National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and
the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine.
Dr. Ralph J. Cicerone and Dr. Charles M. Vest are chair and vice chair, respectively, of the National Research Council.
The Transportation Research Board is one of six major divisions of the National Research Council. The mission of the Transporta-
tion Research Board is to provide leadership in transportation innovation and progress through research and information exchange,
conducted within a setting that is objective, interdisciplinary, and multimodal. The Board's varied activities annually engage about
7,000 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia,
all of whom contribute their expertise in the public interest. The program is supported by state transportation departments, federal
agencies including the component administrations of the U.S. Department of Transportation, and other organizations and individu-
als interested in the development of transportation. www.TRB.org
www.national-academies.org
OCR for page R6
COOPERATIVE RESEARCH PROGRAMS
CRP STAFF FOR NCHRP REPORT 679
Christopher W. Jenks, Director, Cooperative Research Programs
Crawford F. Jencks, Deputy Director, Cooperative Research Programs
Waseem Dekelbab, Senior Program Officer
David Beal, Senior Program Officer (Retired)
Danna Powell, Senior Program Assistant
Eileen P. Delaney, Director of Publications
Hilary Freer, Senior Editor
NCHRP PROJECT 12-77 PANEL
Field of Design--Area of Bridges
Loren Risch, Kansas DOT, Topeka, KS (Chair)
Marcus H. Ansley, Florida DOT, Tallahassee, FL (Deceased)
Theresa Ahlborn, Michigan Technological University, Houghton, MI
Kamal Elnahal, US Coast Guard, Washington, DC
Amy Eskridge, Texas DOT, Austin, TX
Chad E. Knavel, Pennsylvania DOT, Harrisburg, PA
Steven R. Maberry, New Mexico DOT, Santa Fe, NM
Robert J. Peterman, Kansas State University, Manhattan, KS
Basile Rabbat, Portland Cement Association, Skokie, IL
Benjamin A. Graybeal, FHWA Liaison
Stephen F. Maher, TRB Liaison
OCR for page R7
FOREWORD
By Waseem Dekelbab
Staff Officer
Transportation Research Board
This report provides an evaluation of existing AASHTO LRFD Bridge Design Specifica-
tions relevant to the use of high-strength reinforcing steel and other grades of reinforcing
steel having no discernable yield plateau. The report also includes recommended language
to the AASHTO LRFD Bridge Design Specifications that will permit the use of high-strength
reinforcing steel with specified yield strengths not greater than 100 ksi. The material in this
report will be of immediate interest to bridge engineers.
The AASHTO LRFD Bridge Design Specifications allow the use of reinforcing steel con-
forming to many different AASHTO and ASTM materials specifications, but limit the spec-
ified yield strength to 75 ksi. Reinforcement is now available that has yield strength in excess
of 75 ksi. Typical steel reinforcement has well-defined yield plateaus whereas high-strength
reinforcing bars generally do not. The higher strength and the lack of a well-defined yield
plateau could alter structural behavior and do not satisfy some of the design assumptions
in the AASHTO LRFD Bridge Design Specifications. Research was needed to evaluate the use
of high-strength reinforcing steel in structural concrete.
The research was performed under NCHRP Project 12-77 by a team led by Dr. Bahram
Shahrooz at the University of Cincinnati, Cincinnati, OH. Recommended revisions to the
AASHTO LRFD Bridge Design Specifications to permit reinforcing bar yield strengths not
exceeding 100 ksi were investigated and validated for concrete strengths up to 10 ksi and in
some instances up to 15 ksi.
A number of deliverables are provided as appendices. These appendices are not published
herein but are available on the TRB website (Go to http://trb.org/Publications/Public/
PubsNCHRPProjectReports.aspx and look for NCHRP Report 679). These appendices are
titled as follows.
· APPENDIX A--Material Properties
· APPENDIX B--Flexural Resistance of Members with Reinforcing Bars Lacking Well-
Defined Yield Plateau
· APPENDIX C--Strain Limits for Tension-Controlled/Compression-Controlled and Strains
to Allow Negative Moment Redistribution
· APPENDIX D--Flexure Beam Tests
· APPENDIX E--Fatigue of High-Strength Reinforcing Steel
· APPENDIX F--Shear Beam Tests
· APPENDIX G--Analytical Studies of Columns
· APPENDIX H--Beam Splice Tests
· APPENDIX I--Crack Control
· APPENDIX J--Survey Results
· APPENDIX K -- Design Examples
· APPENDIX L--Proposed Changes to Section 5 of the AASHTO LRFD Specification
· APPENDIX M--2010 AASHTO Bridge Committee Agenda Item
OCR for page R8
AUTHOR ACKNOWLEDGMENTS
The research reported herein was performed under NCHRP Project 12-77 by the Department of Civil
and Environmental Engineering (CEE) at the University of Cincinnati in collaboration with the Univer-
sity of Pittsburgh and Henry G. Russell, Inc.
The principal investigators (PIs) on this project were Bahram M. Shahrooz (PI) and Richard A. Miller
(Co-PI) from the University of Cincinnati, Kent A. Harries (Co-PI) from the University of Pittsburgh, and
Henry G. Russell (Co-PI) from Henry G. Russell, Inc. Graduate students Jonathan Reis and Elizabeth
Ward (University of Cincinnati) and Amir Soltani and Gabriel Zeno (University of Pittsburgh) performed
the research under the supervision of the PI and Co-PIs. The experimental component of the research was
completed at the University of Cincinnati Large Scale Test Facility (UCLSTF) and the Watkins-Haggart
Structural Engineering Laboratory (WHSEL) at the University of Pittsburgh. David Breheim at the Uni-
versity of Cincinnati is acknowledged for his technical assistance in various aspects of testing at UCLSTF.
Daniel Kuchma of the University of Illinois at Urbana-Champaign is acknowledged for his early contri-
butions to this project. The PIs wish to express their appreciation to Prestress Services, Melbourne, Ken-
tucky, for fabrication of prestressed girders.
All A1035 reinforcing steel used in this study was provided by MMFX Inc. Hilltop Concrete in Cincin-
nati and Frank Bryan Concrete in Pittsburgh are gratefully acknowledged for their efforts in getting the
concrete mixes used "just so."
Panel member Marcus H. Ansley, who passed away suddenly on June 16, 2010, is sincerely thanked for
his major contributions to this project. His pioneering research on flexural and shear performance of
members using A1035 reinforcement was invaluable. His insistence on examining ductility of flexural
members with A1035 reinforcement helped the research team develop revised strength reduction factors.
The research team would like to dedicate this report to Mr. Ansley.
OCR for page R9
CONTENTS
1 Summary
5 Chapter 1 Background
5 1.1 Introduction
6 1.2 Objective of NCHRP Project 12-77
6 1.3 Literature Review
6 1.3.1 Mechanical Properties of A1035 Reinforcing Steel
7 1.3.2 Tension Properties of A1035 Reinforcing Steel
8 1.3.3 Flexural Reinforcement
9 1.3.4 Shear Reinforcement
10 1.3.5 Compression Members
10 1.3.6 Bond and Development
11 1.3.7 Serviceability Considerations
13 1.3.8 Corrosion Performance of Reinforcing Steel Grades
14 1.4 Survey of Use of High-Strength Steel Reinforcement in Bridge Structures
15 1.4.1 Survey of Use of Stainless Steel Reinforcement in Bridge Structures
15 1.4.2 Reported Use of A1035 Reinforcing Steel in Highway Bridge
Infrastructure
16 Chapter 2 Research Program and Findings
16 2.1 Research Approach
16 2.2 Mechanical Properties of Reinforcing Steel
16 2.2.1 ASTM A1035 Reinforcing Steel
18 2.3 Flexural Reinforcement
18 2.3.1 Flexural Resistance
21 2.3.2 Tension-Controlled and Compression-Controlled Strain Limits
for High-Strength ASTM A1035 Reinforcing Bars
23 2.3.3 Moment Redistribution
23 2.3.4 Experimental Evaluation
25 2.3.5 Summary and Recommendations
26 2.4 Fatigue Performance of High-Strength Reinforcing Steel
27 2.4.1 AASHTO Fatigue Equation and Design with High-Strength Steel
27 2.4.2 Effect of High-Strength Steel on the AASHTO Fatigue Provisions
28 2.4.3 Fatigue of Slabs (AASHTO LRFD Section 9)
29 2.4.4 Fatigue Test Specimens
30 2.4.5 Summary of Fatigue Tests and Conclusions
32 2.5 Shear Reinforcement
32 2.5.1 Shear Resistance
32 2.5.2 Experimental Evaluation
37 2.6 Shear Friction
38 2.6.1 Experimental Program
40 2.6.2 Experimental Results
43 2.6.3 Conclusions with Regard to Shear Friction
OCR for page R10
43 2.7 Compression Members
44 2.7.1 Column Capacity
45 2.7.2 Spacing of Spiral Reinforcement
48 2.7.3 Summary and Conclusions
48 2.8 Bond and Anchorage
48 2.8.1 Splice Development
50 2.8.2 Hook Anchorage
55 2.8.3 Summary and Conclusions
55 2.9 Serviceability Considerations
56 2.9.1 Deflections of Flexural Members
57 2.9.2 Crack Widths
58 2.9.3 Summary and Conclusions
59 Chapter 3 Recommendations, Conclusions,
and Suggested Research
59 3.1 Summary of AASHTO LRFD Clauses Having Recommended Changes
59 3.1.1 Proposed Changes to Section 3 of the LRFD Specifications
59 3.1.2 Proposed Changes to Section 5 of the LRFD Specifications
59 3.1.3 Proposed Changes to Section 9 of the LRFD Specifications
61 3.2 Conclusions
61 3.2.1 Yield Strength
61 3.2.2 Flexure
62 3.2.3 Fatigue
62 3.2.4 Shear
62 3.2.5 Shear Friction
62 3.2.6 Compression
62 3.2.7 Bond and Development
62 3.2.8 Serviceability--Deflections and Crack Widths
62 3.3 Recommended Research
62 3.3.1 Application in Seismic Zones 2, 3, and 4
63 3.3.2 Fatigue
63 3.3.3 Shear Friction
63 3.3.4 Moment Redistribution
63 3.3.5 Control of Flexural Cracking and Corrosion
64 References
68 Notation
72 Appendices
Note: Many of the photographs, figures, and tables in this report have been converted from color to grayscale
for printing. The electronic version of the report (posted on the Web at www.trb.org) retains the color versions.
