CFRP strands for flexural strengthening of steel bridges

This paper explores the use of Carbon fiber reinforced polymer (CFRP) material for strengthening of steel bridges. The research work includes an experimental program to study the effectiveness of using very small diameter CFRP strands, configured in a sheet format, for strengthening of steel structures. The experimental program includes scaled steel-concrete composite beams strengthened with this material at the bottom flange of the steel beams to increase the flexural capacity. The parameters that were considered in the experimental program were the type of CFRP, reinforcing ratio and type of loading. The two types of CFRP materials that were examined for strengthening are High Tensile CFRP and High Elastic Modulus CFRP material. The three types of loading investigated were Static, Cyclic and Fatigue loadings. Test results were used to determine the most effective strengthening system. The selected system was tested under fatigue and cyclic loading. This paper describes the experimental program, presents test results, including the failure modes, and provides guidelines for the design of flexural strengthening system for steel structures.