Seismic performance of innovative adaptive-slit composite structural walls with ultra-high axial compression ratio

This study experimentally investigated the seismic performance of innovative adaptive-slit composite structural walls. A total of four walls were designed to satisfy the seismic performance target of collapse prevention after super-high intensity seismic events. Test parameters were axial compression ratio, reinforcement ratio, and volumetric ratio of stirrups. Test results and adaptive-slit mechanism were summarized and discussed. The specimens were tested under large displacement reversals without losing axial load capacity under ultra-high axial compressive ratio. The reasons are (i) embedded steel tubes increased axial load and deformation capacity of the boundary elements, (ii) arrangement of overlapped hoops effectively confined concrete in compression and improved the integrity of the wall, and (iii) the adaptive-slit mechanism of the proposed wall controlled the propagation of shear cracks and prevented shear failure.