A study on the effect of externally bonded composite plate–concrete interfaces

This paper presents a numerical model to simulate the interface fracture behavior of concrete strengthened with composite plate. The developed model uses lattice-based elements and nonlinear fracture mechanics concepts are addressed to investigate the interface failure behavior. The material properties for concrete and interface are assigned probabilistic, and a normal distribution with c.o.v 10% is used for the probabilistic approach. Numerical simulations of direct shear specimen and four point bending RC beams are conducted to investigate the interface bond stress distribution, load–displacement response and failure mechanism. Parameter studies are carried out to investigate the effect of interface material properties—elastic modulus, tensile strength, and fracture energy—on the behavior of concrete specimen strengthened with external composite plate. The predicted responses from the numerical analysis are found to be in good agreement with experimental values.