An interphase model for the analysis of the masonry-FRP bond

The present paper deals with the problem of the detachment of fiber reinforced polymer (FRP) from a masonry support. In particular, a new interphase model simulating the mechanical bond between masonry and FRP is proposed. It is obtained as a system of two interfaces: one reproduces the response of the glue and of the skin-deep layer and it is characterized by a linear elastic behavior whereas the second describes the nonlinear response of the detachment layer. The effect of the possible confinement due to the stress components acting in the plane of the detachment layer is also considered. Two numerical applications are reported. The first illustrates a comparison between the experimental laboratory tests and numerical simulations, showing the good performances of the proposed model. The second application is specifically devoted to the investigation of the effects of the presence of mortar joints in the detachment mechanism.