Critical Temperature of Steel Beams on the Basis of a Load-Bearing Fire Test of 2-Storey Rigid Steel Frame

Abstract

This paper discusses, on the basis of experimental results, structural fire behaviour of a rigid steel frame with fully-moment-resisting beam-to-beam connections with splice plates and high strength bolts, and beam-to-column connections with full penetration welds. The test results indicated that the moment-resisting connections in the rigid steel frame have sufficient load-carrying capacity, but failure may occur in the connected beam due to inadequate shear resistance of the beam web in fire. The critical temperature of the steel beam could be approximated on the basis of its inherent resistance at elevated temperature and initial effects, because the thermal stress disappeared at the fire limit stage. In this study, the safety factor of structural fire safety design was also discussed on the basis of the result of these load-bearing fire tests.