State of the art regarding interface bond behavior between FRP and concrete based on cohesive zone model

The exceptional mechanical characteristics, corrosion resistance, and high strength-to-weight ratios of fiber-reinforced polymer (FRP) materials have led to their extensive usage in civil engineering. And the bond performance at the FRP–concrete interface is the most crucial factor affecting the effectiveness of reinforcement with FRP. This paper provides a comprehensive review of the application of the cohesive zone model (CZM) in analyzing bond behaviors in FRP–concrete interfaces. It explores the historical development, key modeling techniques, and effectiveness of the CZM in predicting interface behavior under various loading conditions. Different finite-element methods are compared to verify the advantages of the CZM, including its ability to account for the nonlinear behavior of materials and to accurately simulate crack propagation, interface separation, and energy dissipation in different structural forms. The effects of parameters such as fracture-energy ratios, FRP plate thickness, bond length, friction coefficients, peel angles, normal stresses, elastic moduli, and slip rates on the stripping behavior are analyzed, and the necessity of considering coupled damage effects under mixed-mode conditions is emphasized. Additionally, this paper discusses the challenges and development directions associated with the CZM, such as parameter determination, convergence difficulties, and limited application in cyclic- and fatigue-loading scenarios. Thus, this paper emphasizes the benefits of CZM in forecasting important phenomena, including fracture propagation, interface separation, and energy dissipation, while analyzing its drawbacks that require attention in future studies.