Experimental research on mechanical behavior of recycled concrete-filled square steel tubular short columns under axial compression

摘要

By performing the axial compression experiments of 9 recycled concrete-filled square steel tubular short columns (RCFSST) with different recycled coarse aggregate replacement ratio η of core concrete and width-thickness ratio D/t of steel tube, the damage feature of specimens under the action of axial pressure were observed. The paper analyzes the impact of the η, the D/t on the loading-longitudinal displacement curves of specimens. The results show that the failure patterns of the recycled concrete-filled steel tube columns are similar to ordinary concrete-filled steel tube columns, and the whole specimens are shear failure pattern. With the recycled coarse aggregate replacement ratio η decreasing, the descent stage of load-displacement curves is steeper, but the difference of the bearing capacity of specimens with different D/t is far closer. It shows that the result, which takes the negative influence of recycled aggregate into account, would be more reasonable.