Fire resistance of structural steel

During a fire a structural member may be exposed to heating at extremely high temperatures, and as a consequence its strength may decrease substantially in a short time. To prevent such loss of strength it is essential to protect the member against excessive temperature rise. One of the problems in selecting appropriate protection is the evaluation of its effect on the fire performance of the member. Usually fire performance is determined by subjecting a member to a standard fire. In practice, however, the severity of fire conditions can vary over a wide range. The influence of fire severity on the fire performance of steel members, as well as the influence of other important factors that determine their fire resistance, are examined.Lors d'un incendie, un \ue9l\ue9ment de structure peut \ueatre expos\ue9 \ue0 des temp\ue9ratures extr\ueamement \ue9lev\ue9es, ce qui risque de r\ue9duire sa r\ue9sistance de facon tr\ue8s marqu\ue9e en un temps tr\ue8s court. Pour pr\ue9venir cette perte de r\ue9sistance il est n\ue9cessaire de prot\ue9ger les \ue9l\ue9ments de structure contre une \ue9l\ue9vation excessive de temp\ue9rature. L'un des probl\ue8mes de s\ue9lection de la protection appropri\ue9e est l'evaluation de ses effets sur la r\ue9sistance \ue0 l'incendie de l'\ue9l\ue9ment lui-m\uea me. Habituellement, la r\ue9sistance au feu est d\ue9termin\ue9e en soumettant l'\ue9l\ue9ment \ue0 un feu normalis\ue9. En pratique, toutefois, la gravit\ue9 des incendies peut varier consid\ue9rablement. L'article examine influence de la gravit\ue9 des incendies sur la performance des \ue9l\ue9ments en acier ainsi que l'influence des autres facteurs qui d\ue9terminent la r\ue9sistance au feu.Peer reviewed: YesNRC publication: Ye