Repair of Damaged Steel-Concrete Composite Girders Using Carbon Fiber-Reinforced Polymer Sheets

The aging infrastructure of the United States requires significant attention for developing new materials and techniques to effectively and economically revive this aging system. Damaged steel-concrete composite girders can be repaired and retrofitted by epoxy bonding carbon fiber-reinforced polymer (CFRP) laminates to the critical areas of tension flanges. This paper presents the results of a study on the behavior of damaged steel-concrete composite girders repaired with CFRP sheets under static loading. A total of three large-scale composite girders made of W355×13.6 A36 steel sections and 75-mm-thick by 910-mm-wide concrete slabs were prepared and tested. One, three, and five layers of CFRP sheet were used to repair the specimen with 25, 50, and 100% loss of the cross-sectional area of their tension flange, respectively. The test results showed that epoxy bonded CFRP sheet could restore the ultimate load-carrying capacity and stiffness of damaged steel-concrete composite girders. Comparison of the experimental and analytical results revealed that the traditional methods of analysis of composite beams were conservative.