COMPRESSION TESTS OF CONCRETE-FILLED DOUBLE CIRCULAR STEEL TUBULAR STUB COLUMNS
Liping WANG 1*, Xing-Xing CAO 1, Fa-Xing DING 1 and Yi SUN 1
1 School of Civil Engineering, Central South University, Changsha, China.
This paper presents an experimental study on the behavior of the concrete-filled double circular steel tubular (CFDT) stub columns under axial loading. Four groups of stub column specimens were tested in this study. Different parameters of concrete strength, steel ratio and diameter ratio were designed for the test specimens and their effects on the mechanical behavior of CFDT stub columns were examined respectively. The test results regarding the bearing capacity, the ductility as well as the strain ratio were discussed in detail. It was found that increasing the concrete strength will enhance the ultimate bearing capacity of the CFDT columns, while increasing the steel ratio (ρ) and diameter ratio (d/D) will slightly improve the ductility of the CFDT columns. Furthermore, a practical formula in the literature was used for predicting the ultimate bearing capacity of CFDT columns. The predicted results are generally conservative compared with the experimental data both completed in this study and collected in existing literatures.
Concrete-filled double circular steel tubular (CFDT) stub columns; Ultimate bearing capacity; Ductility index; Strain ratio; Diameter ratio