Durability of concrete with CFRP wrapping

Carbon fibre-reinforced polymer (CFRP) material has a high strength-to-weight ratio and good resistance to corrosion and environmental attacks. It has been widely used in rehabilitation of aged infrastructure. However, the durability of the strengthened system has not been yet assessed thoroughly since most of the previous study was conducted based on accelerated tests while the long-term investigation was less reported. This paper investigated the effect of CFRP wrapping on the axial behaviour of concrete cylinders subjected to different environments for more than 13 years. The specimens were exposed to five different conditions, including standard curing, immersion in distilled water, immersion in saturated Na2SO4 solution, outdoor sheltered from the rain, and outdoor without shelter from the rain. Axial compression tests were performed on the wrapped concrete cylinders. The load-bearing capacity and stress-strain responses were recorded. It was found that CFRP wrapping could effectively improve the ultimate strength and ductility of the columns. Though scatter existed, no significant effect of the environmental exposure on the load-bearing capacity of the cylinder specimens was observed which indicates a good durability of the strengthening system