Thermal Behaviour of a Gypsum Fibre Board Associated with Rigid Polyurethane Foam under Standard Fire Conditions

Due to its low thermal conductivity (λ ≈ 20 mW/m.K), rigid polyurethane (PUR) foam has the potential to improve the thermal performance of buildings without increasing the thickness of construction elements. Nevertheless, PUR foam has the drawback of having a low resistance to fire: non-flaming thermal degradation of PUR starts at temperatures about 150-180°C, and flashignition around 300°C. Taking advantage of the stable behaviour of gypsum fibre at high temperature, a new panel composed of gypsum fibre and PUR has been developed, with the objective of resisting to fire for 30 minutes. At first, the thermal properties of the different materials at high temperature have been established. Then, a heat transfer model using temperature-dependent thermal properties and apparent specific heat capacity has been developed. Finally, the model has been compared to full-scale test results performed according to EN 1365-1.