The Effects of Different Constitutive Compression Models of Concrete on the FRP-Concrete Bonded Interface

This study presents the selection process of an approximate constitutive compression model of concrete in the simulations of a fiber-reinforced polymer (FRP)-concrete bonded interface because significant effects of compressive strain energy have been found on the ultimate load at the FRP-concrete bonded interface through a reliable finite element (FE) model. In this study, a number of constitutive compression models of concrete are comprehensively reviewed first and then compared to the experimental data from short concrete columns with different compressive strengths, revealing that the models in the third group are in the best agreement with those in physical tests. The effect of residual stress through different cut-off schemes is then investigated on the basis of the FE model validated by the corresponding testing data of the FRP-concrete bonded interface. The aforementioned constitutive compression models with appropriate values for residual stress are employed to investigate their effects on the mechanical behavior in the simulations of the FRP-concrete bonded interface through the validated FE model. Once again, it suggests that the models in the third group are most suitable to simulate the mechanical behavior of concrete at the FRP-concrete bonded interface.