Finite element simulation of RC beams under flexure strengthened with different layouts of externally bonded fiber reinforced polymer (FRP) sheets

Abstract

Current research work is aimed to numerically simulate the failure behavior of Fiber Reinforced Polymer (FRP) strengthened reinforced concrete beams having different FRP reinforcement ratios. Required objectives are achieved by performing a series of bending tests on RC beams carrying different FRP layout and FRP reinforcement ratio. Tested beams were numerically simulated by using a Finite Element Method based computer package. The layouts of the FRP strengthening were decided based upon the FRP reinforcement ratios ranging from fully wrapped beams to the beams having significantly lower FRP reinforcement ratios. Tests results are presented in the form of load-deflection curves for all of the beams and a comparison of different beam strengthening schemes is also presented. Failure patterns of RC beams strengthened with different layouts of externally bonded FRP sheets were also compared. Results of flexural tests on twelve beams specimens and numerical simulation have indicated that CFRP and GFRP can significantly increase the bending and shear strength of retrofitted beams. However, the use of higher FRP reinforcement ratios to get higher strength increment is not advisable as epoxy properties and concrete surface quality plays a vital role to increase flexural and shear strength.