COMPRESSION BEHAVIOUR OF CONCRETE-FILLED COLD-FORMED HIGH STRENGTH STEEL CIRCULAR HOLLOW SECTIONS
Meini Su1*, Ben Young2 and Xuerui Chen1
1 School of Mechanical, Aerospace, and Civil Engineering, The University of Manchester, Manchester, UK
2 Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
Concrete-filled steel tube has been used in tall buildings as it represents excellent structural performance and economic efficiency compared with other structural members. The use of high strength steel in concrete-filled steel tube can reduce the column size and increase the effective space in buildings. The aim of this study is to investigate the structural behaviour of concrete-filled cold-formed high strength steel tubes subjected to compression. This study includes experimental programme and code comparison. A total of 13 stub column tests on concrete-filled high strength steel tubes have been conducted. The 0.2% proof stress (yield stress) and ultimate strength of the cold-formed steel tubes are up to 1100MPa and 1300MPa, respectively, while the concrete grade covers C40, C80 and C120. The high strength steel tubes of circular hollow sections (CHS) were used in this study. The confinement effects of the high strength steel tubes and the effect of cross-section slenderness limit of CHS were addressed. It is shown that the predictions of the Eurocode and American specifications are conservative, despite the fact that the high strength steel tubes of 1100MPa yield stress and high strength concrete grades of C80 and C120 are not covered in the aforementioned specifications.
Concrete-filled steel tube; circular hollow sections; cold-formed; high strength steel; stub column tests