The behavior of reinforced concrete beams strengthened with CFRP plates against shear, subjected to cyclic loads

In the last decade carbon fiber reinforced polymer (CFRP) has been commonly used for strengthening the shear deficient reinforced concrete beams the entire world. Strengthening is aimed to increase the structural characteristics such as shear strength, rigidity or ductility of the whole structure or a part of the structure. Shear failure is brittle and it becomes without advance warning. Therefore, it is dangerous and unwanted case. In this study, eight RC beams without transverse steel reinforcement have been tested under cyclic load to investigate shear behavior of CFRP plates. Seven specimens were strengthened with side bonded and -jacketed CFRP plates and remaining one was chosen as a reference beam. Anchorages were applied all beams that strengthened CFRP plates. The variables of this work are number of CFRP ply, arrangement and inclination of CFRP and type of CFRP. According to test results, all CFRP arrangements of CFRP plates improved the strength and energy consumption capacity of the RC beams significantly. Specimen that strengthened with two ply bidirectional -jacketed CFRP plates has reached its flexure capacity. Experimental results were compared with the analytical approaches that were suggested by ACI-440 Committee report, Concrete Society TR55 technical report, Colotti et al. and Specification for Structures to be Built in Disaster Areas (SSBDA, 2007).