EXPERIMENTAL STUDY ON THE HEATING MECHANISM AND THERMAL RESPONSE OF A STEEL BEAM UNDER CEILING EXPOSED TO LOCALIZED FIRES

Abstract

Heat flux distribution to the steel beam supporting a ceiling exposed to an isolated fire source on the floor has been modeled by experiments using propane porous burners. Test conditions were chosen to cover the range in which the benefit of the "localized-source" assumption be the most significant. Heat flux on the upper and lower flange and the web are correlated against the flame length , which is further correlated against the ceiling-beam-fire geometry and the size and intensity of the fire source. The experiments demonstrate that temperature at the stagnation point of the beam in this configuration is reduced significantly than uniformly heated surface due to the high conductivity of the steel.