ABSTRACT
The results of tests conducted on 14 concrete-filled steel tubular columns are reported. The primary test parameters were the radius and thickness of test specimens, the concrete strength, the concrete height, the position of diaphragms and the loading conditions. The position of steel local buckling depended on the concrete height, the position of diaphragm and loading conditions. The position of concrete cracking was not always the same as that of steel local buckling. High ductility was obtained by filling tubular columns with concrete and diaphragms.
