Structural Behavior of Reinforced Pre-Compressed Concrete (r.c.) Structures in Fire: Paradigms and Lessons from Experience

In this paper two case studies are discussed with particular regard to the structural behavior of reinforced concrete during fire; remarks are based on the reports of the fire brigade. The fire load was recreated and the fire spread simulated in order to understand the true thermal load acting on the structural elements. As a preliminary result we ascertained a considerable difference between the actual fire resistance R and the requested one (usually 120 min). The reason for such a difference is frequently found in the lack in design details and in insufficient care in assembling the elements of the structure. As a consequence some elements can fall abruptly from their position without the development of plastic hinges, as assumed by the current calculation methods.