Experimental evaluation of CFRP-strengthened shear walls with various CFRP configurations

This paper evaluates the seismic performance of carbon fiber reinforced polymer (CFRP)-strengthened shear walls under various CFRP configurations. A comprehensive experimental investigation was conducted on five shear walls specimens. One specimen served as un-strengthened reference specimen, while the remaining four were respectively strengthened using horizontal, X-shaped, combined, and fully wrapped CFRP strips. Based on the test results, the effects of CFRP configurations on the failure modes, shear bearing capacities, and deformation capabilities were thoroughly evaluated. At the same CFRP ratio, the combined strip method significantly enhanced the shear bearing capacity by 27.8 % compared to the un-strengthened specimen. In contrast, the Xshaped strip method showed a limited increase in shear bearing capacity of 6.39 %. Further analyses on the strengthening efficiency of different CFRP configurations revealed that horizontal strips method exhibited the highest strengthening efficiency for the shear strength, stiffness, ductility, and energy dissipation, while the Xshaped method exhibited the least effectiveness due to early debonding of the CFRP strips. Finally, the actual shear contribution of CFRP obtained from experiments were compared with the predicted values from current standards, with the comparison results revealing an overestimation of the CFRP shear contribution. To improve the accuracy of CFRP shear contribution predictions, the effective strain reduction coefficient capturing the effects of CFRP configurations was proposed.