The Study on Ductility of Thin-walled Square Concrete-filled Steel Tubular Short Columns Configured with Binding Rebars

To better solve the problems of local buckling and stability of thin-walled concrete-filled steel tubular short columns and improve the ability of specimens' overall deformation, long or short binding rebars were set up and anchored on the inner surfaces of the steel tubes; meanwhile the static load test was performed. The results show that the main factors affecting the bearing capacity are steel pipe wall thickness, concrete strength, binding rebars in turn and the ductility is concrete strength, binding rebars, wall thickness. Long or short rebars also significantly improve the deformation properties of specimens. Taking the common specimens' average ductility factor of 2.30 as a benchmark, the average factor of specimens configured with short rebars is 2.85, increased by 24% and configured with the long is 3.34, increased by 45%. Deformation properties of the specimens substantially increase and security of the structure enhances after setting up rebars.