Abstract: By performing the tests of six specimens under axial compressive loads,the effects of the replacement ra- tio of recycled coarse aggregate and the depth-to-breadth ratio of sections on the failure pattern,the load versus de- formation relationship and the bearing capacity of the rectangular recycled aggregate concrete-filled steel-tubular (ＲACFST) stub columns were investigated.The results show that,as the recycled coarse aggregate replacement ra- tio increases,the bearing capacity,the composite elastic modulus and the relative bearing capacity index of the rec- tangular RACFST specimens decrease，while the later bearing capacity index of the specimens increases,and that,the depth-to-breadth ratio has a small effect on the relative bearing capacity index of the specimens,and the later bearing capacity index of the specimens decreases with the increase of the depth-to-breadth ratio.Finally,by selec- ting a rational constitutive model of two kinds of materials,a finite element analysis model was constructed to simu- late the compressive behavior of the rectangular RACFST stub columns.It is found that the simulated results accord well with the measured ones.

Key words: rectangular recycled aggregate concrete-filled steel tube, stub column, recycled coarse aggregate re- placement ratio, depth-to-breadth ratio of section, compressive behavior, finite element analysis