Increased fire resistance of a steel beam using oriented standard board cladding-a thermal analysis

This article presents the possibility of increasing the fire resistance of a steel member with the use of an OSB (Oriented Standard Board) cladding. Correct design and dimensioning of the OSB cladding to fulfil the targeted fire resistance of the steel member is the main challenge with this type of cladding. The problem lies in the addition of combustible material on the surface of the steel member. When the wood-based material burns, additional heat is generated, and this raises the temperature of the surrounding gas. However, wood material benefits from its extraordinary behaviors when exposed to fire. The burned part forms a char layer that insulates the solid materials below it. It is necessary to ensure the integrity of the cladding and to prevent its premature failure. The aim of the work presented in this article was to determine the functionality of an OSB cladding as a fire protection layer for a steel beam. For this purpose, an FE (Finite Element) model of the heat transfer is developed and is validated against measured data from a fire test in a horizontal furnace. The progression of the charred layer is determined from the validated FE model, and is compared with the standard linear charring rate.