Durability Performance of Carbon Fiber-Reinforced Polymer in Repair/Strengthening of Concrete Beams

Adhesively bonded carbon fiber-reinforced polymers (CFRPs) have been widely used as externally epoxy-bonded reinforcement for repair and retrofit of existing concrete structures. This study examines durability aspects of these repairs. Concrete specimens with externally bonded CFRP composite systems were exposed to various ambient real-time and accelerated aging environments including elevated temperature, water immersion, and real-time solar exposure. Three-point loading and direct tension tests were used to quantify, the strength degradation of CFRP specimens subjected to various environmental exposures. Results indicated the combination of heat and moisture rapidly deteriorated the bond strength. As CFRP systems are increasingly used to strengthen reinforced concrete, the need to evaluate the long-term behavior remains a critical factor. Test results verify that the beam and direct-tension bond tests can be used to obtain durability strength-reduction factors for any CFRP system.