ABSTRACT
The calculation approaches to model the thermal action produced by a fire on a structure is described in Eurocode 1 Part 2. Different representations of the effects of fire are given: temperature-time relationships, zone models or localised models. Some considerations are given hereafter on various aspects related to the calculation of temperatures in steel sections depending of the type of representation of the fire. The fire severity to be used for design depends on the legislative environment and
on the design philosophy. In a prescriptive code, the design fire severity is usually prescribed by the code with little or no room for discussion. In a performance based code, the design fire is usually recommended to be a complete burnout, or in some cases a shorter time of fire exposurewhich only allows for escape, rescue, or firefighting (Buchanan 2001). The equivalent time of a complete burnout is the time of exposure to the standard test fire that would result in an equivalent impact on the structure.
