Background and limitations of the Eurocode parametric fire curves, including the fire decay phase

The research study investigates the background and assumptions behind the definition of the Eurocode Parametric Fire Curves (EPFC), the most adopted methodology to replicate natural fire exposures on structural elements. The analysis explores the fire heating phase, as well as the fire decay phase. Particularly, a numerical analysis is carried out to explicitly quantify the maximum temperature, the cooling rate and the duration of the fire decay phase for a reference compartment. Results show that, for both ventilation- and fuel-controlled conditions, the fire decay phase can largely vary in function of the opening factor and fuel load density. Also, comparing empirical temperature-time curves from large-scale fire tests (BRE Cardington 1999-2000) and the calculated EPFC evidences that the EPFC constant cooling rates are not appropriate to correctly characterise the thermal exposure to structural elements during the fire decay phase.The research study investigates the background and assumptions behind the definition of the Eurocode Parametric Fire Curves (EPFC), the most adopted methodology to replicate natural fire exposures on structural elements. The analysis explores the fire heating phase, as well as the fire decay phase. Particularly, a numerical analysis is carried out to explicitly quantify the maximum temperature, the cooling rate and the duration of the fire decay phase for a reference compartment. Results show that, for both ventilation- and fuel-controlled conditions, the fire decay phase can largely vary in function of the opening factor and fuel load density. Also, comparing empirical temperature-time curves from large-scale fire tests (BRE Cardington 1999-2000) and the calculated EPFC evidences that the EPFC constant cooling rates are not appropriate to correctly characterise the thermal exposure to structural elements during the fire decay phase.C