Pressure–impulse diagrams of RC beams considering fire–blast interaction

When analyzing military, defense, or structures/infrastructures deemed critical, explosion-induced actions—often associated with malicious actions—play a significant role. The combined effect of a blast and fire is not uncommon: in fact, an explosion can be the extreme consequence of a fire or vice versa, a fire can occur as the result of an explosion. Although advanced numerical approaches can be a proper solution for analyzing critical structures and infrastructures subjected to accidental actions, their complexity makes these approaches unsuitable for the analysis of ordinary buildings or even for the preliminary design of structures. A pressure–impulse diagram is an easy and common tool that can be adopted to verify the safety of structural members for a wide range of blast scenarios even considering the damage caused by a previous fire. This study aims to compare different approaches that can be adopted for the construction of pressure–impulse diagrams of reinforced concrete structures subjected to a blast and a blast preceded by fire. Taking as a reference case a statically indeterminate beam with three supports, this work presents the influence of the methods of analysis on the safety level assessed through pressure–impulse diagrams.