Axial compressive behavior of rubberized concrete-filled steel tube short columns

Abstract

With different volume replacement ratios of rubber fine aggregate and thicknesses of steel tube, 12 rubberized concrete-filled steel tube (RuCFST) columns were fabricated. Then axial compressive tests were completed. The test results show that RuCFST columns exhibit lower axial compressive capacity and higher ductility than normal CFST columns. The steel tube of the RuCFST with a high rubber replacement ratio is more prone to local buckling and the axial load-displacement curves of RuCFST columns tends to exhibit hardening post-peak response. Based on the experimental results, the relationship between the critical value of the confinement coefficient and the rubber replacement ratio of RuCFST columns was obtained. Then, the axial compressive strength of RuCFST columns was investigated by Eurocode4, AISC360-16 and GB 50936-2014 codes. The results show that the predictions by those codes are conservative. Finally, by considering the higher ductility of RuCFST columns and full use of material properties, a modified formula to calculate the compressive strength of RuCFST columns was proposed and then validated by the experimental results.