Failure mechanism of a curved RC shear wall subjected to cyclic loading: Experimental findings

Reinforced concrete (RC) shear walls with a curved cross-section are appealing structural elements to architects and engineers due to the aesthetic and structural advantages. Owing to the paucity of decent experimental research on curved RC shear walls (CRCSWs), the seismic response of these structural elements is essentially unknown. Therefore, to provide an insight into the overall behavior of CRCSWs and to fill the existing gap, an state-of-the-art experimental testing platform is designed and constructed, which includes a loading system apparatus capable of accommodating displacements of the specimen. A sophisticated monitoring system is also utilized to capture localized as well as full-field deformation data, and record all the rotational movements in the orthogonal directions due to the torsional deformations experienced in the curved RC shear wall. The special configuration of the test unit, test apparatus, as well as the construction process are discussed in detail. The CRCSW is tested pseudo-statically subjected to the fully reversed, lateral cyclic loading. In working to accomplish the objectives of this study, a new number of interesting experimental observations and outcomes have been obtained including the progression of damage, failure mechanism, hysteresis response, effective stiffness, displacement ductility factor, and dissipated energy characteristics. The paper concludes with an investigation into the lateral load resisting performance of the wall under the combined flexural and torsional moments, where it is observed that the induced torsion due to the curved shape of the wall cross-section is responsible for the intensified failure at the tips of the wall, especially at the base level. The findings also reveal that CRCSW can offer a stable hysteretic response with no premature failure, which is a favorable feature regarding the seismic resistance behavior. Finally, as the current design codes recommend no specific provisions for the CRCSWs, the experimental evidences presented in this study are generally expected to provide a benchmark for future investigations dealing with the analysis and design of CRCSWS under seismic actions.