Durability of CFRP-Strengthened Concrete Members Under Extreme Temperature and Humidity

Abstract Fibre reinforced polymer (FRP) systems have emerged as one of the most promising and affordable solutions for strengthening civil engineering infrastructure. Nowadays, this application is widely used in outdoor structures such as bridges, silos and towers. The major challenge in composites applications for outdoor structures is the long-term durability of bond between FRP and substrate under different environmental conditions. Elevated temperature and humidity are common issues that may have adverse effects on the polymer matrix, especially on thermosetting adhesives such as epoxies. This paper presents the results of long-term bond performance of carbon fibre reinforced polymer (CFRP) strengthened concrete members. CFRP- plated concrete specimens were exposed to combination of cyclic temperatures (20–50 °C) and 90% constant humidity. In addition to environmental exposure, some of the specimens were subjected to sustained loading. At the end of the exposure period, the residual strength was measured using single lap shear test method.