Concrete Filled Steel Tube under Axial Compression

The steel tube in a Concrete Filled Tubular Column (CSFT) acts as both longitudinal and lateral reinforcement and is thus subjected to biaxial stresses. The advantages of CSFT over other composite members are that the steel tube provides formwork for the concrete as well as the filled-in concrete prevents local buckling of the steel tube wall and concrete spalling can be avoided. As a whole the stiffness of the member increases due to composite action compare to conventional steel members. The confinement effect is also playing a big role on the load carrying capacity of CSFT.