Effect of Interfacial Properties on the Behaviour of Retrofitted Members

Few contributions are available concerning the effect of interfacial properties on the behaviour of retrofitted beams using fibre reinforced polymers. In this paper, finite element analyses of the test specimens from literature were carried out to investigate the effect of interfacial parameters such as, fracture energy, local shear stress and interfacial stiffness on the retrofitted beam performance. Results from the analyses reveal that the load-carrying capacity is significantly influenced by interfacial parameters, fracture energy, local shear stress and interfacial stiffness. Higher shear stress and fracture energy increase the composite action by increasing the maximum load and delaying debonding. The stiffness of the FRP-concrete interface was found to influence the load-carrying capacity and axial strain in FRP. The axial strain in FRP increases by increasing the stiffness of the FRP-concrete interface.