Abstract：Drop weight setup was used to experimentally study the impact resistance of concrete-filled steel tube (CFT) after exposures to high temperature. The influences of the high-temperature, impact velocity, impact energy, steel ratio and axial load level on the impact resistance of CFT under fire exposure are discussed. The stress-strain relation, the force and compressive deformation versus time history relations of the tested specimens were recorded to analyze the impact behaviors of CFT columns after exposure to high temperature. The test results show that the influences of the high-temperature, impact velocity, impact energy, steel ratio have remarkable effects on the dynamic behaviors of CFT columns after exposure to high temperature, but the influences of axial load level is not remarkable. The compressive deformations and residual deformations would increase obviously with increasing the high-temperature and impact velocity, axial load level, but decrease with increasing the steel ratio. Although the CFT specimens after exposure to high temperature suffered remarkable compressive deformations, the ductility of CFT decreased, the composite columns still remained in good integrity. The test results show that CFT after exposure to high temperature has an excellent impact-resistance.
2011, Vol. 30 
