Experimental tests and numerical simulation of eccentrically loaded SRRC filled square steel tube columns

Abstract

To investigate the mechanical properties of the eccentrically loaded steel reinforced recycled concrete filled square steel tube columns, 14 specimens of the columns were designed and tested. The failure modes, load-displacement curves, bearing capacity and deformation of specimens were obtained and analyzed in detail. In addition, the numerical model of columns considering the unfavorable effects of recycled coarse aggregate (RCA) and the restraint effect of square steel tube were also established by ABAQUS software. The results show that the deflection deformation on the mid-span section of columns was obvious and the failure mode of compression-bending occurred to the eccentrically loaded columns. The replacement percentage of RCA has some adverse effect on the eccentric compression performance of columns. Compared with ordinary concrete columns, the eccentric bearing capacity of columns fully using RCA is reduced by 9.53%. As the increasing eccentricity and slenderness ratio, the maximum reduction on the eccentric bearing capacity of columns was 46.14% and 25.86%, respectively. In addition, the increasing strength of RAC or steel effectively improves the eccentric bearing capacity of columns, but the ductile deformation of columns decreased gradually. Based on the above analysis, a modified calculation formula on the eccentric bearing capacity of columns was proposed.

Keywords

• recycled aggregate concrete
• steel-reinforced recycled concrete
• concrete-filled steel tube
• eccentrically loaded columns
• mechanical properties