Effect of the concrete compressive strength on the structural behaviour of the steel concrete composite cloumn

Composite column has been popularly used in buildings, which are mainly subjected to forces and end moments. There are two types of the steel concrete composite columns: open sections partially or fully encased in concrete, and concrete-filled hollow steel sections. The first type of section has used for fireproof and the slender structural steel can be protected buckling by the exterior concrete, while the remaining type can prevent the transverse deformation of the concrete inside and enhance the load capacity. The steel tube serves as a formwork for casting the concrete, which reduces the construction cost. In this study, four the steel concrete composite columns with concrete-filled hollow steel sections were tested to investigate the effect of the concrete compressive strength on the structural behaviour of the steel concrete composite columns. The parameters observed are load capacity, longitudinal and transverse deformation of the tube steel and the concrete, and the column failure.