Effects of temperature, relative humidity and outdoor environment on FRP-concrete bond

This paper presents the results of an experimental study undertaken to investigate the effects of temperature, relative humidity and exposure to outdoor environment on externally bonded FRP-concrete connection performance.Two types of FRP, namely, carbon and glass, were externally bonded to concrete prisms of 300mm length, 200mm width and 150mm height with two part epoxy impregnation resin and the specimens were exposed to three different environmental conditions for extended durations. The bond strengths of control (unexposed) and exposed specimens were investigated by single-lap-joint shear test (pull-out test). Results of exposed specimens were compared to those of control specimens in terms of bond strengths, strain profiles and failure modes. Based on the results to date, the most significant degradation of bond strength was observed in specimens exposed to outdoor environment. Distinct change in behaviour of FRP-concrete bond has been observed from strain profiles plotted at different levels of applied loads after being exposed to three different environmental conditions.