%0 Journal Article
%T Scrutinizing Gypsum Board Thermal Performance at Dehydration Temperatures
%J Journal of fire sciences
%D 2011
%A Kontogeorgos, D.
%A Mandilaras, I.
%A Founti, M.
%V 29
%N 2
%P 111-130
%X This article investigates the thermal performance of gypsum boards in the dehydration temperature region, where pronounced chemical reactivity is anticipated. Gypsum board samples were gradually heated up to 300°C, using a low heating rate. Temperature measurements at pre-selected board locations indicated three distinct stages of gypsum dehydration; free moisture evaporation, transformation of calcium sulfate dihydrate to calcium sulfate hemi-hydrate and of calcium sulfate hemi-hydrate to calcium sulfate anhydrate. Physical properties of the gypsum board sample, that is density, specific heat, and thermal conductivity, were measured as a function of the dehydration temperature range. Results suggested that the thermal conductivity of the calcium anhydrate sulfate is higher than that of the hemi-hydrate, despite the fact that gypsum porosity increases during the dehydration process. Based on the experimental results, correlations for the thermal conductivity and the dehydration energy as a function of the mass loss during the dehydration process and the initial water content of the gypsum board, respectively, were obtained.<p />
%G en
%I SAGE Publishing
%@ 0734-9041
%U http://dx.doi.org/10.1177/0734904110381731