Using Micro-Scale and Solid Material Data for Modelling Heat Transfer in Stone Wool Composites Under Heat Exposures

Abstract

AbstractModelling capabilities have drastically improved in the last decade. However, in most of the cases the fire response of building elements is predicted by fitting input material properties to the models in order to match test data. This paper presents models developed to predict the unexposed side temperature of stone wool layered composites with stainless steel or gypsum claddings exposed to severe heat conditions. The suitability of material thermal properties from literature and reaction kinetic parameters obtained at bench scale (e.g. thermogravimetric analysis, bomb calorimeter, slug test) to model composites at different heat exposures is studied. Modelling efforts include: (1) the combustion of the organic content of the wool, (2) diffusion term to account for the passage of hot air through the wool, (3) calcination reactions in the gypsum plasterboard, (4) energy released by burning of the paper lining of gypsum plasterboard. The models are compared against experimental data. Results show that material thermal properties of gypsum plasterboard and stone wool retrieved from the literature and obtained at a bench scale provide accurate model predictions under different heat exposures. Furthermore, reactions schemes for the dehydration of gypsum plasterboard and organic content combustion in the wool also provide good modelling results. Further analysis is necessary to understand the environmental conditions inside the layered composites in fire exposures in order to achieve better modelling predictions.