Seismic performance of resilient recycled aggregate piloti-type structure employing ultra-high strength bars

Abstract

A resilient recycled aggregate piloti-type brick masonry structure equipped with ultra-high strength bars (UHSB) in the pilotis and shear walls was proposed. Quasi-static test and finite element analysis based OpenSees were conducted to study its seismic performance. The main parameters include different steel bar categories, reinforcement configurations, storey stiffness ratios and shear wall distributed reinforcement ratios. The results revealed that both the recycled aggregate concrete (RAC) frame-shear wall structure at the first storey and the upper recycled brick masonry structure showed satisfactory deformation performance and stable load-carrying capacity. The frame-shear wall structure at the weak first storey is prone to suffer from shear failure of the shear wall under the relatively large drift due to the larger proportion of shear deformation. The plastic damage of the pilotis and shear wall reinforced with UHSB was obviously reduced. The arrangement of diagonal UHSB in the shear wall can significantly improve the shear resistance and prevent the premature shear failure of the shear wall, and further enhance the resilience and seismic performance of the bottom-storey structure. The proposed resilient frame-shear wall structure of bottom storey presented excellent repairable performance. The innovative piloti-type brick masonry structure with resilient bottom storey can give full play to the resilience and seismic performance of its bottom-storey frame-shear wall structure even with a relatively higher storey stiffness ratio.