Input data for the natural fire design of building structures

Traditionally, structural fire safety design is based on conventionally rather than on physically based thermal actions. This certainly holds for the international standards in the field, see e.g. [1]. Therefore, the release of Eurocode 1, part 2-2: "Actions on structures exposed to fire" [2], should be seen as a turning point: for the first time in international standardization, the natural fire concept is presented as an - for the time being -informative option. This option opens the possibility for a more nuanced and functionally based design, enabling to achieve rational and uniform fire safety levels. It should be noted however that the Eurocode approach is a first and still incomplete attempt to arrive at more physically based thermal actions. Hence, the aim of this paper is: - to identify the input data, necessary for a natural fire design; to critically discuss the input data, required by EC1, part 2-2; to demonstrate the potential of the natural fire desig