Structural performance and reinforcement improvement of structural walls using strain-hardening cementitious composites

Abstract

Reinforced concrete (RC) shear walls are effective in improving lateral stiffness and load-carrying capacity under earthquake and wind loads. According to the level of seismic design, however, the spacing of reinforcing steel bars should be very narrow and complicated, with tight spacing of tied bars, as is the case with seismically special RC shear wall design. The purpose of this study was to investigate the applicability of strain-hardening cementitious composites (SHCCs) in structural walls in order to improve structural performance as well as the complications with reinforcement details. The SHCC was mixed, and mechanical tests showed that the SHCC exhibited high ductile tensile strains above 2.0%, while sustaining the tensile stress after cracks and developing multiple microcracks, avoiding crack localizations. Six specimens of RC and reinforced SHCC structural walls were designed and manufactured with varying reinforcement details, and experiments on wall specimens were carried out under transverse wall-loading tests. These experiments demonstrated that the use of SHCC in structural walls, despite minimum use of reinforcement ratios, showed improved responses to minimize damage and failure caused by localized cracks under bending and shear to compared with the use of normal reinforcement ratios in RC walls.