Investigation on eccentric compression performance of basalt fiber-reinforced recycled aggregate concrete-filled square steel tubular columns

To compensate for the performance deficiencies as well as expand the application field of recycled aggregate concrete (RAC), this study provides an innovative material-component type of basalt fiber-reinforced recycled aggregate concrete (BFRRAC)-filled square steel tubular columns. The eccentric compression test after being carried out on specimens with varying replacement ratios of recycled coarse aggregate (RCA), eccentric ratio, length-diameter ratio, as well as basalt fiber (BF) content. The failure mode as well as failure process for specimens were witnessed, the load-axial displacement curves were obtained, and the eccentric compression performance for specimens was investigated. According to the results of experimentation, one workable eccentric compression finite element model was generated, soon afterwards the influencing parameters of eccentric compression performance for BFRRAC-filled square steel tube were expanded and analyzed. Moreover, the N-M correlation equation was developed. The results demonstrate that when the length-diameter ratio was 8 and 11, the specimen had large lateral deformation and bending failure, and the upper core concrete was severely damaged. Increasing the eccentric ratio and replacement ratio of RCA decreased the specimen's peak load, with maximum decreased degree is 49.8% and 10.1%, respectively. The eccentric ratio significantly affects the specimen's peak load. Basalt fiber demonstrates somewhat increase in the peak load for specimen, and the increase degree is 7.8%.