ABSTRACT
Fiber Reinforced Plastic (FRP) composites are increasingly used in the rehabilitation and retrofitting of existing concrete structures. A significant application of composites is the strengthening of concrete structures through the external bonding of composite plates or composite sheets (fabrics). Extensive studies have been performed on the structural performance of FRP-reinforced concrete structures, which have shown significant increases in stiffness and more favorable failure modes than conventional designs. The uses of composite plates or fabrics as external reinforcement have considerable potential in infrastructure applications. However, there is a concern about the reliable performance of the FRP-concrete bonded interface, which can be susceptible to delamination (debonding) under mechanical loading (static and fatigue) and degradation after exposure to environmental conditions, such as moisture, sea water and freeze-thaw. An inadequate interface bond strength and integrity can lead to premature failure of a reinforced concrete member. Therefore, there is an urgent need to investigate the delamination and degradation of FRP-concrete bonded interfaces.
An overview of the performance of FRP-concrete bonded interfaces is presented in this paper. The current status on applications and characterization of externally reinforced concrete structures is reviewed, with emphasis on bond strength and interfacial fracture resistance. New promising techniques for further investigation of FRP-concrete bonded interface are proposed, and the outcome of this review is used to make recommendations for future work on fundamental aspects for proper analytical predictions and experimental evaluations of performance of FRP-concrete bonded interfaces.
