An Analytical Model to Predict Flexural Behavior of NSM FRP-Strengthened RC Beams Subject to Debonding Failure

摘要

An analytical model is proposed in this study to predict the flexural behavior of reinforced concrete (RC) beams strengthened with near-surface mounted (NSM) fiber reinforced polymer (FRP) reinforcements due to debonding failure. In modeling the RC beam-NSM FRP system, a trilinear bond-slip relation is adopted for the interfacial stress between the two components. A closed-form solution is obtained by imposing appropriate boundary conditions for bond stress, FRP strain and deflection of the strengthened beams. The results are verified by the comparison with experimental data from different studies, where satisfactory correlation is obtained such as flexural deflection and tensile strain of FRP reinforcement. A parametric study is further conducted, which shows that the diameter of the FRP reinforcement and the steel rebar significantly affects the flexural performance of the NSM-strengthened RC beams. The Young's modulus, the compressive strength of concrete and the bond strength of FRP reinforcement improve the performance to a lesser extent.