Study on shear performance of CFRP grid-reinforced UHPC panel

Due to the lightweight properties and exceptional durability, carbon fiber reinforced polymer-reinforced ultra-high performance concrete (CFRP-UHPC) panels are well-suited for engineering structures such as bridges and marine infrastructure. Based on the combination of experiments and digital image correlation (DIC), this study evaluates the effects of different CFRP reinforcement ratios, shear span ratios, and boundary conditions on the shear strength, failure modes, and energy dissipation of panels. Based on the peak-load DIC principal strain localization characteristics, it is evident that both simply-supported and fixed-end panels exhibit three distinct failure modes. The load-carrying capacity of simply-supported panels increases only marginally beyond 0.32% reinforcement, suggesting that 0.32% is the ideal reinforcement threshold for engineering applications. For fixed-end panels, under low reinforcement ratios and small shear span ratios, the shear capacity is lower than that of simply-supported panels. As the reinforcement ratio increases (=0.66%), cracks in the tension zone are controlled, stable arching effects form, and bearing capacity is significantly increased. Moreover, the study revised existing shear strength formulas for panels and fabrics and proposed a simplified prediction model for CFRP-UHPC panels, providing a theoretical foundation for future engineering applications.