Experiment on T-Shaped CFT Stub Columns with Binding Bars Subjected to Axial Compression

Abstract

To improve the mechanical behavior of T-shaped concrete-filled steel tubular (T-CFT) column, the method that setting binding bars along the height of steel tube is proposed. Five T-CFT stub columns with binding bars and another two without binding bars subjected to axial compression were tested. The influences of the spacing and diameter of binding bars on the failure modes, maximum strength, and ductility of T-CFT stub columns are investigated. The experimental results demonstrate that by setting binding bars or decreasing the spacing of binding bars, the buckling modes of the steel plates are changed, the local buckling of the steel plates is postponed, and the confinement effects on the core concrete can be improved significantly. By setting binding bars, the bearing capacity and ductility of the columns are enhanced by 1.17 and 3.38 times at most, respectively. By increasing the diameter of binding bars, the ductility of the columns is improved, but the bearing capacity and buckling strength cannot be improved when the diameter is large enough.