STUDY ON PERFORMANCE OF EXPOSED H-SECTION STEEL COLUMN IN FIRE
To study the performance of an exposed H-section steel column,we developed a fire test furnace.Six specimens were studied,considering the differences of axial compression ratios and restrictions.The temperatures of furnace gas and steel columns,lateral and axial deformations of steel columns,and the additional axial force for limited axial deformation were measured.The results show that: the same section's temperature is almost the same when the exposed steel columns encircled by fire;the axial deformation of steel columns with the same height is almost the same,restrictions are enhanced,and the axial deformations are slightly smaller;the axial compression ratio increases when axial deformations are restricted and the additional axial force decreases,but the sum is not necessarily small.Throughout the course of experiment,the behavior of steel columns in fire is clearly divided into two stages of expansion and compression,expansion is main and compression phase is very short.Although the temperature of steel columns is very high,the steel columns can withstand the axial pressure steady and produced very small lateral deformations.