Abstract
The flexural behavior of concrete filled square steel tubular (CFT) columns using high strength materials is experimentally investigated. Tests are carried out on sixteen CFT specimens subjected to uniform bending under a constant axial load. The experimental load-deformation curves are compared with analytical curves using our proposed stress-strain relationships. On the bases of the comparisons, a simple calculating method for flexural capacities of high strength square CFT columns is proposed. One of the features of our calculating method is that the applicable ranges are wide for material strengths and width-to-wall thickness ratio of CFT columns. The ranges of the concrete strength and the yield stress of steel tube are from 18.6 (MPa) to 119 (MPa) and from 194 (MPa) to 781 (MPa), respectively. The range of the width-to-wall thickness ratio of CFT column is from 22.7 to 98.0. The proposed calculating method is calibrated by the total of sixty-two experimental capacities.
