Integrating experimental bond-slip models intro finite element modeling of CFRP-strengthened concrete prisms

The overall performance and failure mechanisms of externally bonded concrete structures with fiber-reinforced polymers (FRP) sheets/plates are significantly influenced by the bond behavior between FRP composites and concrete substrates. Finite element (FE) modeling and analysis depend on an accurate description of this bond-slip connection. This study represents the integration of experimental bond-slip models into finite element simulations of concrete prisms reinforced with carbon fiber-reinforced polymers (CFRP) sheets. For CFRP-to-concrete joints, experimental bond tests were carried out in a three-point bending configuration to determine bond-slip relationships. Cohesive zone modeling approaches were then used to implement the resulting bond-slip curves into a nonlinear FE model. The experimental data from CFRP-strengthened concrete prisms tests under various conditions were used to verify the FE model. The findings demonstrate the ability of the proposed FE approach incorporating experimentally derived bond-slip models to accurately capture the complex behavior of CFRP-strengthened concrete elements including debonding failures. Moreover, this paper demonstrates the significance of accurate bond characterization and offers a framework for better finite element modeling of reinforced concrete structures using fiber-reinforced polymers, allowing for more accurate structural evaluations and design optimizations.