Fire tests of load-bearing LSF walls made of hollow flange channel sections

• Conducted fire tests of LSF walls made of hollow flange channel (HFC) sections
• Time–temperature and deflection profiles, and failure times are presented for LSF walls with varying configurations.
• Conventional cavity insulation led to inferior fire performance of walls.
• Determined the effect of load ratio on the thermal and structural performances of LSF walls
• LSF walls made of HFC studs provided superior fire performance than conventional LSF walls.

Fire resistant and load bearing Light gauge Steel Frame (LSF) wall systems are generally made of cold-formed steel stud sections lined with gypsum plasterboards. Structural stability of these steel frames at elevated temperatures is important for the load bearing LSF walls for survival during fire events. The studs in these frames are usually Lipped Channel Section (LCS) studs. However, there are other more structurally efficient stud sections such as the hollow flange section studs, which can be effectively used in LSF walls. However, lack of fire research on these sections has inhibited their usage in LSF walls. This paper proposes the use of hollow flange channel (HFC) section studs in LSF walls with a view to increase their fire resistant ratings (FRR). In this study, five full scale fire tests of LSF walls made of welded hollow flange channel section studs were conducted under standard fire conditions. Three different wall configurations and three load ratios were considered in these tests. This paper presents the details of fire tests and their results including the time-temperature profiles of plasterboard and steel stud surfaces, lateral displacement and axial deformation profiles, failure modes and failure temperatures. It also presents the effects of using different wall configurations and load ratios on the FRR of LSF walls. Comparison of the fire performance of LSF walls made of welded HFC section studs with those made of conventional LCS studs demonstrated the superior fire performance through the use of welded HFC section studs.