Effect of bonded lengths and wrappings on energy capacity and debonding strain of reinforced concrete beams strengthened with carbon‐fiber‐reinforced polymer

In this study, a series of flexural tests were performed to evaluate the energy capacity and debonding strain of reinforced concrete beams strengthened with a carbon‐fiber‐reinforced polymer (CFRP). Seven reinforced concrete beams were fabricated and loaded up to failure in a three‐point bending test. The type of CFRP laminate (plate or sheet), bonded length (1.44 or 2.16 m), and wrapping of the CFRP sheet were selected as the key test variables. The test results showed that beams strengthened with CFRP sheets were more effective than those strengthened with CFRP plates. The CFRP‐strengthened beams showed an elastic energy greater than that of the control beam, but the opposite result was obtained for the plastic energy. The average debonding strains of the CFRP plates and sheets were 4,309 and 11,649 μ, respectively, which corresponded to 21.5% and 77.1% of their respective ultimate tensile. POLYM. COMPOS., 38:1418–1426, 2017. © 2015 Society of Plastics Engineers