Retofitting of Reinforced Concret Bwams Using CFRP Flexural and Shear

Abstract

In this paper, thirty three tests were conducted on 200x400x3250 mm full-scale reinforced concrete beams retrofitted in flexural and shear using Carbon Fiber-Reinforced Polymer (CFRP) laminates. All beams were tested under four-point bending. The main variables considered were the position and the length of retrofitting of CFRP laminates, six different lengths 500,1000,1500,2000, 2500, and 3000mm were used to retrofit the beams in flexural, while three different position of CFRP, diagonal, vertical and full CFRP strips were applied on the lateral faces of the beams to retrofit the beams in shear. The experimental results, indicated that generally, CFRP laminates help in improving the structure performance by reducing deflections and/or cracking and increasing ultimate strength. The beams retrofitted in shear and flexure by using CFRP laminates are restored to stiffness and strength values nearly equal to or greater than those of the control beams. It was found that the efficiency of the strengthening technique by CFRP in flexure varied depending on the length of CFRP laminates. Also the experimental outcomes prove that CFRP strips distribution can improve the load carrying capacity of the beams retrofitted in shear. The failure modes are controlled by the pre-repair damage flexural crack wherein it causes the CFRP deboning.