Technical Report Documentation Page March 2003 6. Performing
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Technical Report Documentation Page Report No. 2. Government Accession No. 3. Recipient’s Catalog No. FHWA/OH-2003/006 4. Title and subtitle 5. Report Date Environmental/Durability Evaluation of FRP Composite March 2003 Strengthened Bridges 7. Author (s) 6. Performing Dr. Nabil F. Grace Organization Code 9. Performing Organization Name and Address 8. Performing Organization Lawrence Technological University, Civil Engineering Department Report No. 21000 West 10 Mile Rd, Southfield, MI 48075-1058, USA 10. Work Unit No. (TRAIS) 12. Sponsoring Agency Name and Address Ohio Department of Transportation 11.Contract/Grant No. 1980 W Broad Street, Columbus, OH 43223 State Job No. 14718 (0) 15. Supplementary Notes 13. Type of Report and Period Covered Final Report 14. Sponsoring Agency Code 16. Abstract The experimental evaluation of the durability of RC beams externally strengthened with CFRP plates/fabrics is presented. Experimental investigation consisted of testing a total of seventy eight RC beams under various environmental conditions such as 100% humidity, dry-heat, salt-water and alkaline solutions, freeze-thaw and thermal expansion cycles, and repeated load effects. Accelerated aging procedures were used to correlate the strength and stiffness degradation as per ASTM standards. All the test beams were subjected to ultimate load test after appropriate environmental conditioning. A durability based design approach for analysis and design of externally strengthened beams is also presented. This report consists of 6 chapters as given below: Chapter 1- Introduction Chapter 2- Literature Review Chapter 3- Experimental Program Chapter 4- Results and Discussion Chapter 5- Durability based design Chapter 6- Conclusions and Recommendations 17. Keywords Carbon Fiber Reinforced Polymer 18. Distribution Statement Plates, Carbon Fiber Reinforced Fabrics, No restrictions. This document is available to the Reinforced Concrete, Durability, External public through the National Technical Strengthening. Information Service, Springfield, Virginia 22161 19. Security 20. Security Classification 21. No. of pages 22. Price Classification (page) unclassified 319 (Report) Unclassified LAWRENCE TECHNOLOGICAL UNIVERSITY ENVIRONMENTAL/DURABILITY EVALUATION OF FRP COMPOSITE STRENGTHENED BRIDGES Prepared in Cooperation with the Ohio Department of Transportation and the U. S. Department of Transportation, Federal Highway Administration Contract No. 14718 (0) by Nabil F. Grace, Ph.D., PE Project Director Civil Engineering Department Lawrence Technological University Southfield, MI 48075-1058, USA March, 2003 Ohio Department of Transportation- Technical Advisory Group Monique R. Evans Brad Fagrel Vikram Dalal Valerie Frank Karen Pannell Lawrence Technological University- Research Team Nabil F. Grace, Project Director Emad N. Ibrahin, Research Assistant Nate Blackburn, Research Assistant Shamsher B. Singh, Postdoctoral Research Scholar ODOT Contract No. 14718 (0) Project Director: Nabil F. Grace, LTU Keywords: Carbon Fiber Reinforced Polymer (CFRP) CFRP Plate CFRP Fabrics Composite Materials Concrete Dry-Heat Durability Epoxy Environmental Conditioning External Strengthening System Freeze-Thaw Humidity Repeated Loads Alkaline Solution Salt solution Civil Engineering Department Lawrence Technological University Southfield, MI 48075-1058 Tel: 1-248-204-2556; Fax: 1-248-204-2568 The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Ohio Department of Transportation or the Federal Highway Administration. This report does not constitute a standard, specification or regulation. TABLE OF CONTENTS LIST OF FIGURES ...............................................................................................................viii LIST OF TABLES ...............................................................................................................xviii ABSTRACT............................................................................................................................xix ACKNOWLEDGMENTS .....................................................................................................xxi CHAPTER 1 INTRODUCTION............................................................................................1 1.1 STATEMENT OF PROBLEM ..............................................................................................1 1.2 BACKGROUND TO THE FRP SYSTEMS............................................................................2 1.2.1 Historical Development of Externally Bonded FRP System...........................4 1.2.2 Commercially Available Externally Bonded FRP Systems.............................6 1.3 PROJECT OBJECTIVES .................................................................................................21 1.4 EXPERIMENTAL INVESTIGATION..................................................................................22 CHAPTER 2 LITERATURE REVIEW..............................................................................24 2.1 GENERAL.....................................................................................................................24 2.2 EFFECT OF HUMIDITY..................................................................................................24 2.3 EFFECT OF DRY-HEAT.................................................................................................26 2.4 EFFECT OF ALKALINE ENVIRONMENT .........................................................................28 2.5 EFFECT OF REPEATED LOAD........................................................................................31 2.6 EFFECT OF FREEZE/THAW ...........................................................................................32 2.7 EFFECT OF SALT-WATER SOLUTION............................................................................35 2.8 MATERIALS DESIGN VALUES ......................................................................................36 2.8.1 Aerospace-based Determination....................................................................36 2.8.2 Naval and Marine-Based Determination........................................................37 2.8.3 Determination in Infrastructure Applications ................................................37 CHAPTER 3 EXPERIMENTAL PROGRAM ...................................................................39 3.1 OUTLINE OF THE EXPERIMENTAL PROGRAM ...............................................................39 3.2 CONSTRUCTION DETAILS OF TEST BEAMS...................................................................40 3.2.1 Reinforcement Details....................................................................................40 3.2.2 Application of CFRP fabrics and CFRP plates..............................................41 3.3 ENVIRONMENTAL CONDITIONING AND TEST PROCEDURES .........................................43 3.3.1 100% Humidity Exposure..............................................................................45 3.3.2 Dry-Heat Exposure ........................................................................................45 3.3.3 Alkaline Solution Exposure ...........................................................................46 3.3.4 Salt-Water Exposure ......................................................................................47 3.3.5 Freeze/Thaw Exposure...................................................................................48 3.3.6 Thermal Expansion Cycles ............................................................................50 3.3.7 Repeated Load Effects ...................................................................................51 3.4 INSTRUMENTATION AND TESTING PROCEDURE ...........................................................51 3.4.1 Instrumentation..............................................................................................51 3.4.2 Testing Equipment .........................................................................................52 3.4.3 Testing Procedure ..........................................................................................55 CHAPTER 4 RESULTS AND DISCUSSION ....................................................................83 4.1 INTRODUCTION ............................................................................................................83 4.2 BEAMS EXPOSED TO 100% HUMIDITY .........................................................................84 4.2.1 Beams strengthened with CFRP plates ..........................................................85 4.2.2 Beams strengthened with CFRP fabrics ........................................................88 4.3 BEAMS EXPOSED TO DRY-HEAT CONDITION AT 140OF (60OC).....................................90 4.3.1 Beams strengthened with CFRP plates ..........................................................90 4.3.2 Beams Strengthened with CFRP Fabrics.......................................................92 4.4 BEAMS EXPOSED TO ALKALINE SOLUTION AT 73OF (23OC)..........................................94 4.4.1 Beams strengthened with CFRP plates ..........................................................95 4.4.2 Beams strengthened with CFRP fabrics ........................................................97 4.5 BEAMS EXPOSED TO SALT-WATER AT 73OF (23OC)....................................................98 4.5.1 Beams Strengthened with CFRP Plates .........................................................98