Experimental Study of Mechanical Behavior of Concrete Filled Steel Tubular Short Columns after Fire

摘要

Mechanical behavior and bearing capacity of ordinary concrete filled steel tubular short column (NCSSC) and ceramsite concrete filled steel tubular short column (CCSSC) subjected to fire load are experimentally investigated. Effect of the parameters, such as the maximum value of fire temperatures, fire duration on the strength and ductility of the two types of specimens were especially discussed. The test results show that both of the specimens of NCSSC and CCSSC after fire have higher bearing capacity and better ductility, there was no descent segment in load-displacement curves of the most specimens after the fire load was subjected, and even the case that bearing load increased again after descent segment arose. It was concluded that the maximum response temperature of specimens and fire duration time has great effect on the axial bearing capacity of concrete-filled steel tubular short columns subjected to fire, and there is a turning point of temperature for the influence.