Flexure Behavior of Carbon Fiber Reinforced Polymers Retrofitted RC Beams

Carbon fiber reinforced polymers (CFRP) have been widely used for retrofitting of reinforced concrete members over the past three decades. This study presents the experimental results of four reinforced concrete beams retrofitted with CFRP and tested under four point monotonic loading. CFRP strips (Sika Carbo-Dur S812) and wraps (Sika-Wrap 230C) were used in two different patterns to evaluate their effect on the flexural behavior of RC beams. Two beams were first tested until their ultimate capacity, retrofitted with the application of CFRP and re-tested again, and two beams were retrofitted before the application of any load. The CFRP strips provided in the middle one-third of the span with U-shaped anchorage at the ends enhanced the capacity of beams up to 15 percent. The stiffness of the beams were significantly increased as demonstrated by smaller displacement at the ultimate load. However, the CFRP wraps provided without the anchorage didn't enhance the strength due to pre-mature debonding.