Bearing capacity of stub columns composed of structural steel and self-compacting high-strength concrete-filled steel tube:experimental research

Column composed of structural steel and concrete-filled steel tube is a new type of heavyload-carrying composite column.An experimental study on the mechanical properties of the composite column,in which effect of supporting condition has been taken into account,was conducted for 9 short composite columns for the first time.The effect of the confinement coefficient,the structural steel index and concrete strength on the mechanical properties of the composite column was discussed,and formulas for predicting the ultimate bearing capacity of the composite column were proposed.The results calculated by the proposed formulas are in good agreement with the test results.The results show that composite column has very high strength and ductility because of the interaction between the steel tube,structual steel and core concrete,so the composite column can effectively improve the collapse resistant capacity of building.