Simple Estimates of the Most Adverse Fire Growth and Equivalent Fire Severity in Concrete Compartments for Structural Safety

This paper presents two facets of rationalizing natural fires in concrete compartments for structural fire safety . The paper proposes the rate of fire growth corresponding to the maximum possible peak temperature in a compartment, followed by an equation to estimate the equivalent severity between the standard and a natural fire using an energy-based approach. Standard fire curves, applied universally for all design conditions may over- or under-predict real compartment fires. Meanwhile, a full-fledged performance-based design is neither practical nor straightforward to employ in every design situation. The Eurocode parametric temperature–time curves enable engineers to account for specific compartment characteristics, including compartment geometry, building materials, fuel load, and ventilation. Given that different structural fire safety design approaches entail varying levels of complexity, this paper presents simple methods to estimate the worst-scenario compartment fire characteristics . Additionally, fire ratings are established only using standard fire curves, necessitating a scientific means of determining an equivalent severity between natural and standard fires. The energy-equivalence approach used in this paper to establish an equivalent fire severity yields more consistent results than traditional equivalent fire severity methods and empirical formulae for concrete compartments. The proposed equations are developed using simulations of compartment fires and provide insights into the ventilation characteristics that result in the worst-case scenario for both the rate of fire growth and the equivalent time.