Structural performance of composite steel rubberised concrete members under combined loading conditions

Abstract

AbstractThis paper investigates the structural behaviour of rubberised concrete‐filled steel tubular (RuCFST) members under a wide range of axial‐bending loading conditions. The results of an experimental programme on circular concrete‐filled steel tubes (CFST), incorporating conventional and rubberised concrete (RuC) materials with various rubber content ratios, are presented. After describing the specimen details and testing arrangements, the influence of the RuC infill on the behaviour of test members in terms of moment‐axial interaction and ductility, is examined. The test results show that whilst the cross‐sectional capacity of RuCFST members is reduced with the increase in rubber content, significantly higher ductility is obtained compared with conventional counterparts. An enhancement of about 85% in ductility is obtained for members with 60% rubber content compared to those with conventional concrete. Finally, the test results are compared with current design guidelines, indicating that the latter tend to overestimate the capacity, particularly for relatively high rubber contents.