Strand Debonding in Pretensioned Beams

265 Pages·2012·8.56 MB·English

SCHOOL OF
CIVIL ENGINEERING
INDIANA
DEPARTMENT OF TRANSPORTATION
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JOINT HIGHWAY RESEARCH PROJECT
Part 1 Final Report
FHWA/INDOT/JHRP-92-24
Strand Debonding in Pretensioned Beams i
- Precast Prestressed Concrete Bridge
:
Girders with Debonded Strands
:
Continuity Issues
O.A. Abdalla, J.A. Ramirez, and R.H. Lee
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PURDUE UNIVERSITY
JOINT HIGHWAY RESEARCH PROJECT
Part 1 Final Report
FHWA/INDOT/JHRP-92-24
Strand Debonding in Pretensioned Beams
- Precast Prestressed Concrete Bridge
Girders with Debonded Strands
Continuity Issues
OJi. Abdalla, JA. Ramirez, and R.H. Lee
Digitized by the Internet Archive
in 2011 with funding from
LYRASIS members and Sloan Foundation; Indiana Department of Transportation
http://www.archive.org/details/stranddebondingiOOabda
Purdue University
Ed)
Final Report
School of Civil Engineering
Strand Debonding in Pretensioned Beams - Precast Prestressed Concrete Bridge
Girders with Debonded Strands.
Part 1, Continuity Issues
June 1, 1993
Proj.No. :C-36-56B
File No. : 7-4-28
To: Vincent P. Drnevich, Director
Attached is Part 1, of 2, Final Report of a research project entitled, "Strand Debonding in
Pretensioned Beams" By O.A. Abdalla, J. A. Ramirez, and R.H. Lee. The report considers
the comments of the advisory committee.
Respectfully submitted,
Julio A. Ramirezyand R.H. Lee, Co-Principal Investigators
cc: A. G. Altschaeffl J. D. Flicker J. A. Ramirez
P. L. Bourdeau K. R. Hoover G. F. Rorbakken
M. D. Bowman R. B. Jacko C. F. Scholer
M. J. Cassidy L. S. Jones G. B. Shoener
L. M. Chang R. H. Lee K. C. Sinha
S. Diamond C. W. Lovell D. L. Tolbert
J. J. Dillon R. H. Lowry R. Vancleave
W. L. Dolch D. W. Lucas C. A. Venable
V. P. Drnevich B. G. McCullouch T. D. White
A. A. Fendrick B. K. Partridge L. E. Wood
J. R. Wright
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CIVILE
ENGINEERING
PURDUE
UNIVERSITY
1284 Civil Engineering Building • West Lafayette. IN 47907-1284
TECHNICAL REPORT STANDARD TITLE PAGE
1. Report No. 2. Government Accession No. 3. Recipient' i Catolog No.
FAWA/IND0T/JHRP-92
4. Title and Subtitle S. Report Date
Debonding in Pretensioned Beams-Precast
Junft L 1993
Prestressed Concrete Bridge Girders with Debonded 6. Performing Organization Code
Strands- Part 1, Continuity Issues
7. Author(j) ,8. Performing Organ. lotion Report No.
O.A. Abdalla, J. A. Ramirez, R.H. Lee FHWA/INDOT/JHRP-92
9. Performing Organization Name and Address 10. Worlr Unit No.
Joint Highway Research Project
11. Contract or Grant No.
Purdue University
1284 Civil Engineering Building
13. Type of Report and Period Covered
12. Sponsoring Agency Nome and Addres* Final Report
Indiana Department of Transportation Executive Summary
State Office Building T,,nP 1 , 1 q«q-M a y 11 1QQ^
14. Sponsoring Agency Code
100 N. Senate Ave.
Indianapolis, IN 46204
IS. Supplementary Note»
Conducted in cooperation with the U.S. Department of Transportation, Federal
Highway Administration, NCP H401A2362
16. Abstroet
This report summarizes an experimental investigation carried out to evaluate
the effects of strand debonding on the behavior of precast pretensioned bridge
members made continuous with a cast-in-place slab and diaphragm. Shear and
flexural capacity were evaluated and the experimental results compared to the
results obtained using the PCA and CTL (proposed) analytical methods.
Four continuous specimens were fabricated and tested. Three specimens con-
sisted of Type-I AASHTO girders continuous with a cast-in-place slab and diaphragm
The fourth specimen consisted of Indiana Type CB-27 box girders also continuous
with cast-in-place slab and diaphragm.
The effect of time-dependent creep and shrinkage deformations on the capacity
of the girders at the continuous supports was investigated in this study. Also
addressed in this report is the effect of limiting the stress at the extreme
compression fiber, near the continuous suppose, to allowable working stress
values on the load carrying capacity of continuous members.
17. Key Words 18. Distribution Statement
Flexural strength, shear strength, No restriction. This document is avail-
blanketed strands, continuous bridges, able to the public through the National
precast construction Technical Information Service
Virginia 22161
19. Security Closslf. (of nSls report) 20. Security Classlf. (of this page) 21. No. of Pages 22. Price
Unclassified Unclassified
Form DOT F 1700.7 (8-89)
11-
ACKNOWLEDGEMENTS
Thanks are extended to the advisory committee members especially Mr. Scott
Herrin and Mr. Steve Toillion for their suggestions and helpful comments in finalizing
the report.
The prestressed concrete girders tested in this investigation were manufactured by
Hydro Conduit Corporation in Lafayette, Indiana. Their cooperation and contributions
in the instrumentation, manufacture and transportation of the beams are also
appreciated.
Sincere thanks are expressed to Karl Schmid and Chris Ogg who tested the first two
specimens. Thanks are extended to Russ Maurey, Doug Cleary and Hendy Hassan for
their help during the experimental phase of this project
Financial support was provided by the Federal Highway Administration and the
Indiana Department of Transportation through the Joint Highway Research Project,
School of Civil Engineering, Purdue University, West Lafayette, IN. Their cooperation
and encouragement are appreciated.
Ill
TABLE OF CONTENTS
Page
V1
LIST OF TABLES
vu
LIST OF FIGURES
xx
NOTATION
xxm
ABSTRACT
l
CHAPTER 1 - INTRODUCTION .
3
CHAPTER 2 EXPERIMENTAL PROGRAM
J
2.1 Objective and Scope
2.2 Description and Fabrication of Test Specimens • 4
4
2.2.1 Precast Beams Construction and Instrumentation
6
2.2.2 Slab and Diaphragm Construction
2.3 Materials
'
2.3.1 Concrete...
'
2.3.2 Prestressing Steel
8
2.3.3 Non-Prestressed Reinforcement
°
2.4 Continuous Tests
2.4.1 Specimen 1
jjj
10
2.4.1.1 Cracking
ll
2.4.1.2 Deflections
ll
2.4. 1.3 Concrete Bottom Fiber Strains
12
2.4.1.4 Stirrup Strains
12
2.4.1.5 Longitudinal Bar Strains
13
2.4. 1.6 Strand Strains
14
2.4.2 Specimen 2
14
2.4.2.1 Cracking
15
2.4.2.2 Deflections
15
2.4.2.3 Concrete Bottom Fiber Strains
15
2.4.2.4 Stirrup Strains
16
2.4.2.5 Longitudinal Bar Strains
16
2.4.2.6 Strand Strains
1
- IV
Page
2.4.3 Specimen 3 17
2.4.3. Cracking 17
2.4.3.2 Deflections 18
2.4.3.3 Concrete Bottom Fiber Strains 18
2.4.3.4 Stirrup Strains..... 19
2.4.3.5 Longitudinal Bar Strains 19
2.4.3.6 Strand Strains 19
2.4.4 Specimen 4 21
2.4.4.1 Cracking.... 21
2.4.4.2 Deflections 22
2.4.4.3 Concrete Bottom Fiber Strains 22
2.4.4.4 Stirrup Strains 23
2.4.4.5 Longitudinal Bar Strains 23
2.4.4.6 Strand Strains 23
2.5 Summary 24
CHAPTER 3 - TIME-DEPENDENT EFFECTS ...26
3.1 PCA Method 26
3.2 CTL Method 28
3.3 Evaluation of Time-Dependent Effects 28
3.4 Summary 32
CHAPTER 4 - SUPERIMPOSED LOAD EFFECTS 33
4.1 Introduction 33
4.1.1 Effective Strand Stress 33
4.1.2 Continuity for Superimposed Load.............. ....34
4.1.3 Flexural Cracking..... 35
4. 1.4 Web-Shear Cracking 36
4.1.5 Flexure-Shear Cracking 40
4.1.6 Ultimate Shear Strength 43
4.1.7 Flexural Capacity of Negative Moment Region 45
4.1.8 Bottom Fiber Stress Evaluation 48
4.1.9 Summary 52
CHAPTER 5 - SUMMARY AND CONCLUSIONS 54
5.1 Summary 54
5.2 Conclusions 55
5.3 Future Work 58
LIST OF REFERENCES 59
- V -
Page
APPENDICES
Appendix A - Time-Dependent Restraint Moments 62