Tests on Cyclic Behavior of Concrete-Filled Hollow Structural Steel Columns after Exposure to the ISO-834 Standard Fire

摘要

The strength and seismic behavior of a composite column may be used to assess the potential damage caused by fire and help to establish an approach to calculate the structural fire protection for minimum posture repair. This paper provides new test data pertaining to the seismic behavior of concrete-filled hollow structural steel (HSS) columns after exposure to fire. The test parameters included the sectional types, the fire duration time and the axial load level (n). Thirteen concrete-filled HSS column specimens, including seven specimens with circular sections and six specimens with square sections were tested under constant axial load and cyclically increasing flexural loading. Comparisons are made with predicted column strengths and flexural stiffness using the existing codes. It was found that concrete-filled HSS columns after exposure to fire exhibit very high levels of energy dissipation and ductility. Generally, the energy dissipation ability of the columns with circular sections was much higher than those of the specimens with square sections. The work in this paper provides a basis for further theoretical study on the seismic behavior of concrete-filled HSS columns after exposure to fire.