Seismic performance of shear deficient exterior RC beam-column joints repaired using CFRP composites

Abstract

In this paper efficiency and effectiveness of using Carbon Fiber Reinforced Polymers (CFRP) sheets in repairing and upgrading the shear strength and ductility of seismically deficient exterior beam-column joint has been studied. For this purpose, a reinforced concrete exterior beam-column sub-assemblage was constructed with non-optimal design parameters (inadequate joint shear strength with no transverse reinforcement) representing pre-seismic code design construction practice of joints and encompassing the vast majority of existing beam-column connections. The specimen was subjected to cyclic lateral load histories so as to provide the equivalent of severe earthquake damage. The damaged specimen was repaired using CFRP sheets and then subjected to the similar cyclic lateral load history and its response history was obtained. Response histories of the specimen before and after repair were then compared. The results were compared through hysteretic loops, load-displacement envelops, ductility and stiffness degradation. The comparison shows that CFRP sheets improve shear resistance and