CFRP-strengthened shear walls: Combined effects of CFRP and reinforcement ratio

This study presents a three-dimensional numerical model based on the Hashin damage criteria to assess the seismic performance of Carbon Fiber Reinforced Polymer (CFRP)-strengthened Reinforced Concrete (RC) shear walls, accurately capturing the rupture of CFRP strips. The effectiveness of various CFRP-concrete interface modeling methods in capturing CFRP debonding was initially discussed. A series of numerical simulations were then conducted to investigate the combined effects of the CFRP ratio and the horizontal reinforcement ratio on the seismic behavior of CFRP-strengthened shear walls. The results indicate that an increase in the CFRP ratio reduces the failure degree of shear walls, as the shear damage shifts progressively from the concrete and horizontal reinforcement to the CFRP strips. However, an increase in the horizontal reinforcement ratio counterproductively weakens the shear-strengthening effect provided by the CFRP strips. To specifically evaluate the shear contribution of the CFRP strips, a novel coefficient was proposed and validated, capturing the combined effect of the CFRP ratio and the horizontal reinforcement ratio on the shear contribution of the CFRP strips. This coefficient provides a quantitative measure to optimize the reinforcement design of RC shear walls.