Finite Element Modeling of RC Beams Strengthened in Flexure Using FRP Material

Finite element modeling has been performed using finite element code CASTEM to predict the flexural response of rectangular RC beams strengthened with externally bonded fiber reinforced polymer (FRP) materials by various techniques. Damage model for plain concrete, elastic perfectly plastic behavior for steel bars, elastic–plastic isotropic behavior for steel–concrete interface, linear elastic behavior for FRP materials and perfect bond for FRP-concrete interface were adopted for finite element modeling. In order to validate the finite element modeling approach, a comprehensive experimental program was designed and carried out to compare the experimental and the model results. RC beams were strengthened using CFRP and GRFP materials with various techniques and then tested in three point bending. Comparison of modeling and experimental results was carried out in terms of load–deflection response. The results of numerical simulation showed close agreement with the experimental observations. The ability of the finite element modeling technique adopted in this study to predict damage and cracking pattern is also highlighted in this paper.