EXPERIMENTAL STUDY ON RESIDUAL LOAD BEARING CAPACITY OF SRC COLUMNS UNDER AXIAL FORCE AFTER EXPOSURE TO FIRE

This paper provided five test data pertaining to the residual load bearing capacity of steel reinforced concrete (SRC) columns after exposure to fire. Two parameters, that is, slenderness ratio and concrete strength are mainly taken into consideration. Test results show that the failure pattern of SRC columns under an axial pressure force after exposure to fire is basically the same with that at room temperature. When the specimens are destroyed, the internal core steels are still fine, having no local buckling phenomena. Concrete strength and the slenderness ratio are two important factors that affect the strength of SRC columns under an axial pressure force after exposure to fire. For the specimens of about the same slenderness ratios, the higher concrete strength they are, the higher ultimate bearing capacity they have. In the condition of roughly the same concrete strength, the ultimate bearing capacity of specimens reduces with the increase of the slenderness ratio. The ultimate bearing capacity of all specimens at room temperature is calculated on the method proposed by Chinese regulation YB 9082-2006 and JGJ 138-2001. The compared results of experimental values of SRC columns under an axial pressure after the fire hazard and calculating values of SRC columns under an axial pressure at room temperature show that the bearing capacity of SRC columns under an axial pressure after the fire hazard decreases significantly, only about 67% of that under room temperature.