Axial Compressive Behaviour of Recycled Aggregate Concrete Columns Externally Confined by Square Steel Tube

By the axial compression tests on a total of 9 recycled aggregate concrete (RAC) columns confined by square steel tube, the effect of recycled coarse aggregate replacement percentage (RCARP) on the axial compressive strength was studied. Test results indicated that the failure modes of core concrete were diagonal shearing failure. With the increase of RCARP from 0% to 100%, the peak load of specimens decreased 14.5%. The simplified calculative method of bearing capacity was discussed by test data and theoretical analysis, which can provide a reference for engineering designers.