Externally bonded fiber-reinforced polymer for rehabilitation of corrosiondamaged concrete beams

This paper reports the results of an experimental program designed to provi de a realistic assessment of the the potential of using fiber-reinforced po lymer (FRP) materials in the repair and strengthening of reinforced concret e (RC) flexural members. The experimental program included seven RC flexura l beams 270 x 400 mm in cross section and 4350 mm in length. Four of the se ven RC beams Mere reinforced externally with one or two layers of carbon fi ber-reinforced polymer (CFRP) composite. Variables considered in this exper imental program included state of damage (damaged versus undamaged) and loa ding condition during bonding (loaded versus unloaded). Damage was introduc ed in four of the seven RC beams using an accelerated corrosion technique d eveloped at the University of Toronto. Tests in the current study show that it is necessary to consider the effects of corrosion- and load-induced dam age as well as sustained load on the load-carrying and deflection capacitie s of externally reinforced flexural members. Furthermore, it is concluded t hat it is possible to achieve adequate corrosion repair with externally bon ded CFRP and minimal intervention. In particular the current study shows th at it is important to optimize CFRP layout to balance strength recovery wit h control of faulting and splitting, which could lead to premature member f ailure.