抄録
A series of full scale fire resistance tests was conducted to investigate the behavior of concrete-filled tubular (CFT) columns without fire protection under fires. Each column was subjected to both axial and lateral loadings so that a double curvature bending was realized. The test results showed that fire resistance of unprotected CFT columns was significantly affected by factors such as axial force ratio, applied lateral displacement, cross sectional shape and depth-thickness ratio of steel tube, and the method to cast concrete. A local buckling of steel tube at the top or bottom region of column reduced the confinement effect on concrete and caused crush of concrete nearby, which eventually lead to the failure of CFT column.
