Experimental and numerical evaluation of various solutions for fire protection of steel structures

Abstract

Steel structures are commonly used in construction for their high strength/weight ratio and many other advantages. However, due to their thermal conductivity and the decrease of mechanical performance with high temperature, steel structures need to be protected in fire. Various solutions exist to protect steel structures using materials with appropriate insulation performances (intumescent paints, plasterboards, Spray-applied fire-resistant materials). In the present study, common solutions using intumescent paints and plasterboard are tested. Their behaviour is compared to that of solid wood elements used as insulation materials in fire. Experiments in furnace are performed to obtain the evolution of temperature on the steel profiles surfaces. Thus, thermocouples are installed on the steel profile surface and on different depths of timber elements. In fact, even for intumescent paints, limited data exist on the steel profile heating under fire exposure. These data are useful to develop thermomechanical models of steel structures exposed to fire. A numerical model is also proposed to analyze the heating of fire protected steel profile. The results show that wood can be used for fire protection of steel structures in addition to its advantages provided for the mechanical behaviour of hybrid sections composed of steel and timber. This solution contributes to the development of passive protection of steel structures using bio-based materials.