EVALUATION OF SIMPLIFIED CALCULATION METHODS FOR STRUCTURAL FIRE DESIGN

Several simplified calculation methods have been developed for structural fire design. Their function is to bridge the gap between element classification according to design tables, which are often too coarse for practical work, and elaborate scientific computer codes, which remain inaccessible for normal users. The aim of this paper is to compare and evaluate existing analytical methods for fire design of structural elements made of reinforced concrete, structural steel or timber. The fundamentals of these methods are outlined and discussed with regard to fire load, thermal and mechanical high-temperature behaviour of the materials, thermal and mechanical analysis of cross-sections and structures, and safety concept. The existing methods are valuated taking into account different criteria, e.g. consistency, theoretical and experimental verification and applicability of the procedure and input data. The overall uncertainties and deviations from existing test results are determined and covered by a global safety margin.