Study of Post-Fire Bearing Capacity of Self-Stress Ceramsite Concrete Filled Steel Tubes

Mechanical behavior and bearing capacity of self stress ceramsite concrete filled steel tubes (noted as SCCST) after exposure to fire are experimentally studied. Effect of the parameters, such as value of furnace temperatures, self stress on the post-fire bearing capacity and ductility of the specimens after exposure to fire were especially discussed. The experimental results show that all the specimens of SCCST have higher post-fire bearing capacity and better ductility, and there was no obvious descending segment in the load-strain curves of the most specimens after exposure to fire. It was concluded that the furnace temperature subjected to the specimens and the initial self stress produced in the specimens of the composite short columns has some effect on the axial bearing capacity of ceramsite concrete-filled steel tubular short columns after exposure to fire, and the volume of expansion agent of 10% has most great effect on post-fire bearing capacity of SCCST after exposure to fire.