Shear Strengthening of Exterior RC Beam-column Joints with CFRP Sheets

Beam-column connections are key members in moment frames resisting seismic loads which their failure may lead to total collapse of structure. Application of fiber reinforced polymer (FRP) composites has been received much attention in seismic rehabilitation of these members. However, the main challenge facing this technique is the premature debonding of FRP composites off the concrete substrate posed. The present study was conducted to investigate the capability of grooving method (GM) coupled with FRP fan at termination point of FRP composites in postponing or completely elimination of undesirable debonding failure mode in shear strengthened reinforced concrete (RC) joints. To do so, three half-scale RC beam-column subassemblies were tested under reversed cyclic lateral load. Results revealed that GM, coupled with FRP fan at termination point of FRP composites, was able to eliminate altogether the debonding failure mode and remarkable improvement in terms of load-carrying capacity, ductility, and energy dissipation was achieved.