Experimental study on the performance of steel-concrete interfaces in circular concrete-filled double skin steel tube

摘要

The interaction between steel and concrete is important for the functionality of composite tubular construction. In this study, a series of pushout tests were carried to investigate the behaviour of steel tubes to sandwiched concrete interfaces in concrete-filled double skin steel tubes (CFDST). Parameters concerned included the diameter to thickness ratio of both outer and inner steel tubes, the hollow ratio of the cross section, the roughness of steel tube surfaces, the shrinkage of concrete, etc. The bond stress-slip relationships and the strain responses were recorded and analysed, and effects of different parameters were discussed. In general, the bond strength of the outer steel tube to concrete interface for CFDST was comparable with that of concrete-filled steel tube (CFST), and the bond strength of the inner steel tube to concrete interface was higher than that of the outer steel tube to concrete interface.