On the size effect of interfacial fracture between concrete and fiber reinforced polymer

In this study, the size effect of the nominal interfacial strength between concrete and fiber reinforced polymer (FRP) is investigated by integrating fracture tests and computational simulations. Three-point bending fracture tests are performed with geometrically similar specimens to demonstrate the size effect, and to measure fracture parameters for mode-I. Based on the measured fracture parameters, the crack-growth behavior is predicted using the finite-element-based cohesive zone model. Computational results predict accurately the experimental results of the load versus crack mouth opening displacement (CMOD) curves. Furthermore, both the computational and experimental results illustrate that the nominal interfacial strength decreases with increases in the specimen size, i.e., the size effect of the interfacial fracture. Because of the size effect, fracture parameters, such as the fracture energy, should be measured and evaluated to predict the interfacial fracture between concrete and FRP.