Flexural-Shear Behavior of Concrete-Filled Double-Layer Steel Tubular Column

Concrete-filled steel tubular (CFT) column has been widely used in high-rise buildings because of a number of distinct advantages in earthquake zones, such as high lateral capacity and axial compressive strength, large energy absorption capacity, good ductility, and high stiffness. In order to meet the structural performance of the high-rise building as the height of the building increases, a special column with concrete-filled double-layer steel tubes was proposed in previous research. In this study, quasi-static cyclic test of a concrete-filled double-layer steel tubular column (CFDLT column) specimen was carried out under relatively high constant axial force ratio to investigate the effect of steel ratio on the flexural-shear behavior of the column by comparing with the hysteresis loop of the CFDLT column specimen in previous study. Regarding the progress of lateral strength reduction after the ultimate lateral capacity, the CFDLT column specimen with larger steel ratio showed a slight improvement over the other one with smaller steel ratio.