Loadbearing LSF walls exposed to standard fire

This paper describes the behaviour of loadbearing lightweight steel framed (LSF) walls, protected with gypsum board, in six standard fire resistance tests conducted recently by the National Research Council of Canada in partnership with the North American steel industry. The purpose of this test series was to investigate the effects of insulation, resilient channels and stud spacing on the fire resistance of LSF walls. Temperature and deformation data, collected during the tests, is analyzed, and the characteristic patterns in thermal transmission and structural behaviour are identified. The effects of various heating regimes on the change in stud end conditions and the mode of structural failure are discussed. An analytical fire resistance model for loadbearing LSF walls is presented. Temperature histories across wall assemblies are simulated numerically by explicit integration of one-dimensional heat transfer equations. The apparent thermal properties for gypsum board and three types of insulation are calibrated based on full-scale test data. Numerical procedures are presented to simulate lateral deformation histories and predict structural failure times.