LAUSR

Abstract Experimental and numerical studies on the static behaviour of eccentrically compressed recycled aggregate concrete filled steel tube (RACFST) slender columns with rectangular cross-section are reported in this paper. Fifteen specimens were tested under eccentric compression. The factors considered in the experimental investigation included: 1) depth-to-width ratio (β), from 1.0 to 2.0; 2) load eccentricity ratio ( m ), from 0 to 0.6; 3) slenderness ratio ( λ ), from 20 to 40; and 4) recycled coarse aggregate (RCA) replacement ratio ( r ), from 0 to 100%. The experimental results show that failure of the eccentrically compressed specimens is manifested with major local buckling of the steel tube coving compression flange and part of side walls near the mid-height section and the crushing of the concrete core at the same location. The eccentrically compressed specimens generally possess stable load versus deformation curves including the initial linear and the subsequent nonlinear stages before reaching the peak load and the post-peak descending stage. In addition, when other parameters keep constant, the specimens with larger m , λ and r possess smaller bearing capacity ( N ue ), and m has more significant effect on N ue than λ and r . Numerical simulation of the eccentrically compressed rectangular RACFST slender columns is also carried out by a finite element analysis (FEA) model built in ABAQUS, and the model is verified by experimental results. The typical mechanism of rectangular RACFST slender columns under eccentric compression is further revealed by the FEA model. Finally, simplified formulae for the bearing capacity are developed, and the comparison between simplified and experimental results indicates that the simplified model is accurate in predicting the bearing capacity of rectangular RACFST slender columns.