AXIAL COMPRESSION BEHAVIOR OF CONCRETE FILLED STEEL TUBULAR STUB COLUMNS USING HIGH STRENGTH MATERIALS

A lot of study has been executed on the ultimate strength of concrete filled steel tubular columns (CFT). Especially, the confined effect to the filled concrete by the steel tube has been the main subject in these studies. However, in case of the CFT in which high strength materials are used, the contribution of the confinement effect to the ultimate strength has not yet been clarified. Therefore, we did the stub column tests on concrete filled steel tubular short columns which have steel tensile strengths of 400-780MPa and concrete compressive strengths of 20-90MPa. The relationships of failure pattern, deformation capacity and ultimate strength are discussed in this paper based on test results.