Experimental and Finite Element Study of RC Beams Shear Strengthened with Prestressed NSM CFRP

In order to improve the shear performance of prestressed concrete beam bridges and to solve the diseases such as shear cracks in the web and beam deflection, this paper proposed a method of shear strengthening with prestressed near surface mounted CFRP. Four RC T-beams shear strengthened with prestressed NSM CFRP were tested. The mechanical behavior and failure mode of each specimen were investigated, and the variation law of shear cracks was studied. The test results show that prestressed NSM CFRP shear strengthening can significantly increase the shear cracking load and shear capacity. But concrete at the bonded end of CFRP bears the stress caused by prestress tension and load at the same time and is more prone to debond at the concrete cover of the web. Anchorage system such as U-shaped CFRP sheets should be considered to avoid this failure mode. A finite element model based on ABAQUS was established to simulate the concrete plastic damage and the local bond-slip behavior of NSM CFRP. The simulation results show that the ultimate performance and shear crack distribution of the specimen are in good agreement with the test results.