Coupled shear walls (CSWs) are structural elements used in reinforced concrete (RC) buildings to provide lateral stability and resistance against seismic and wind forces. When subjected to high levels of seismic loading, CSWs exhibit nonlinear deformation through cracking and crushing in concrete and yielding in reinforcements, thereby dissipating a significant amount of energy, leading to their permanent deformation. Externally bonded fiber-reinforced polymer (EB-FRP) sheets have proven to be effective in strengthening RC structures against various loading and environmental conditions. In addition, their high strength-to-weight ratio makes them an attractive solution as they can be easily applied without significantly increasing the structure’s weight. This study investigates the effectiveness of using EB-FRP sheets to reduce residual displacement in CSWs during severe earthquake loadings. Two series of 15-story and 20-story CSWs in Western and Eastern Canadian seismic zones, which serve as representative models for medium- and high-rise structures, were evaluated through nonlinear time history analysis. The numerical simulation of all CSWs and strengthened elements was carried out using the RUAUMOKO 2D software. The findings of this study provided evidence of the effectiveness of EB-FRP sheets in reducing residual deformation in CSWs. Additionally, significant reductions in the rotation of the coupling beams (CBs) and the inter-story drift ratio were observed. The results also revealed that bonding vertical FRP sheets to boundary elements and confining enhancement by wrapping CBs and wall piers is a very effective configuration in mitigating residual deformations.

The primary seismic force-resisting system (SFRS) in middle- to high-rise reinforced concrete (RC) building structures often includes coupled shear walls (CSWs) and single shear walls (SSWs). These walls are designed to transfer lateral forces to the foundation and dissipate energy through the development of plastic hinges. The latter lead to residual displacement in these structural components. On the other hand, self-centering systems enable the structures to return to their initial position after severe loading or at least reduce residual displacement. The objectives of this study were, therefore, as follows: (i) to review the state of the art on shear wall self-centering techniques and retrofitting methods based on externally bonded fiber-reinforced polymer (EB-FRP); (ii) to evaluate research needs to improve the self-centering ability of shear walls using EB-FRP.