Experimental Investigation on Shear Strengthening of RC Continuous T-Beams with Different Layer of CFRP Schemes

Carbon fiber reinforced polymer (CFRP) is a material suitable for strengthening the reinforced concrete (RC) beams. Although many in situ RC beams are of continuous constructions, there has been very limited research on the behavior of such beams with externally applied FRP laminate. In addition, most design guidelines were developed for simply supported beams with external FRP laminates. This paper presents the results of a test program for shear strengthening characteristics of strips bidirectional flexible carbon-fiber polymer sheets bonded to reinforced concrete (RC) continuous beams. A total of three beams with size of 150 × 320 × 3650 mm, flange width = 400 mm and flange thickness = 120 mm concrete beams were tested and various sheet configurations and layouts were studied to determine their effects on the ultimate shear strength and shear capacity of the beams. From the test results, it was found that all schemes were found to be effective in enhancing the shear strength of RC beams. It was observed that the strength increases with the number of sheet layers, which provided the most effective strengthening for RC continuous T-beam. Beam strengthened using this scheme showed a 23.21 % increase in shear capacity as compared to the control beam. Two prediction models available in the literature were used for computing the contribution of CFRP strips and compared with the experimental results.