The effectiveness of FRP strips in repairing moderately and severely damaged RC beam–column connections

An effective means to increase the shear resistance of shear deficient reinforced-concrete (RC) beam–column connections is by bonding fibre-reinforced polymer (FRP) composites. The majority of research to date has focused on the strengthening of two-dimensional reinforced-concrete connections with fibre-reinforced polymer; that is, the strengthening of virgin (undamaged) connections. This paper reports the results of tests on the effectiveness of fibre-reinforced polymer strips in repairing two-dimensional connections with different degrees of damage. The results of tests assessing the effectiveness of fibre-reinforced polymer strips in strengthening virgin connections are also reported. All test specimens are extensively instrumented and their behaviour and failure comprehensively documented. In the case of the repaired specimens, instrumentation is concentrated on the fibre-reinforced polymer around the damage region, thus enabling the strength contribution and behaviour of the fibre-reinforced polymer repair to be closely monitored. The results of this experimental programme enable a better understanding of the strengthening and repair effect of fibre-reinforced polymer strips in reinforced-concrete beam–column connections, and the results will also facilitate the future development and calibration of analytical and numerical models.