The 11th International Symposium on Steel Structures, November 3-6, 2021, Jeju, Korea, Jeju-Si, South Korea, 3 - 06 November 2021, pp.1-4
Columns made with circular concrete-filled double skin steel tubes (CFDSTs) possess many advantages over other tubular columns due to their superior structural behavior mainly from confinement effect from the tubes to the infill concrete. Strength and ductility of such columns need to be well determined as these are significant for buildings to be designed in seismically vulnerable areas. In this study, a total of 8 circular tubes including 2 DSTs (double skin steel tubes without infill) and 6 CFDSTs (concrete-filled double skin steel tubes with various parameters) were tested under axial compression to failure to explore their potential structural benefits. Impact of presence/absence of infill concrete, section’s hollow ratio (χ= 0.50 ~ 0.75), and sandwiched concrete type (plain, polypropylene, and steel fibers added) were the experimental parameters. The test results indicated that, compared to DSTs, the CFDSTs had higher strength and ductility. Independent of the fiber reinforced concrete composition, fiber reinforced CFDST specimens with χ= 0.50 hollow ratio have generally better strength than the counterparts with χ= 0.75 hollow ratio.