Seismic behaviors of tailings and recycled aggregate concrete-filled steel tube columns

To alleviate the shortage of river sand and the pollution of construction waste, this paper proposed the tailings and recycled aggregate concrete (TRAC) and its application in concrete-filled steel tube (CFT) columns. Six full-scale TRAC filled square steel tube (TRACFST) columns were tested under axial static load and lateral cyclic load, and the results were verified by the finite element method(FEM). The principal parameters were substitution rate of RAC (0%, 50%, 100%) and axial load ratio (0.3, 0.5). The failure mode of the specimens was presented. Based on the experimental data, the hysteresis curves, skeleton curves, ductility, energy dissipation capacity, and stiffness degradation of the specimens were analyzed. The difference of peak bearing capacity of specimens with different RAC substitution rates was no more than 5%. The average ductility coefficient of the specimens with 100% substitution rate increased by 1%-7% compared with the specimens with 0% substitution rate. The TRACFST columns exhibit remarkable seismic performance.

Automated summary

To address the issues of river sand shortage and construction waste pollution, this study proposes the use of tailings and recycled aggregate concrete (TRAC) in concrete-filled steel tube (CFT) columns. Six full-scale TRAC filled square steel tube (TRACFST) columns were tested under different loads and verified using finite element method (FEM). The study analyzes the failure mode, hysteresis curves, ductility, energy dissipation capacity, and stiffness degradation based on experimental data. The TRACFST columns exhibit excellent seismic performance with a minor difference in peak bearing capacity and an increase in ductility coefficient with higher RAC substitution rate.