Experimental investigation of concrete-filled single-skin and double-skin steel oval hollow section stub columns

Abstract

Both concrete-filled single-skin and double-skin steel tubular stub columns were investigated experimentally in this study. The skin of the composite columns was constructed using steel oval hollow section (OHS) tubes. A series of tests was performed to investigate the effects of the geometric dimension of steel OHS tube and concrete strength on the behaviour and strength of composite columns. The overall width-to-thickness ratio of the OHS tube sections ranged from 15.8 to 62.6. The structural performance of the composite columns was investigated using different nominal concrete cylinder strengths of 40, 70 and 100 MPa. The composite column lengths were chosen so that the length-to-width ratio generally remained at a constant value of 3 to prevent overall column buckling. The concrete-filled OHS tube specimens were subjected to uniform axial compression. The test strengths, load-axial shortening relationship and failure modes of the composite columns were presented in this paper. The test strengths were compared with the design strengths calculated using the American Specification and European Code for composite steel and concrete structures. It was shown that the design strengths do not agree well with the experimental results.