The influence of the expanded clay granules ratio on the thermal conductivity and thermal diffusivity of gypsum plaster-based composites's

Thermophysical properties of building materials such as thermal conductivity and thermal diffusivity are mandatory in any study of thermal performance of buildings. In this work, measurements of these two thermophysical properties were performed on four circular samples prepared by mixing gypsum plaster with different mass proportions of expanded clay granules. The water ratio was kept constant in all mixtures. Then the thermal diffusivity and thermal conductivity were determined using the flash method and the hot plate respectively. Results show that the addition of the expanded clay granules to the gypsum plaster has a negative impact on the thermal properties. This was due to absorption of the mix water and plaster by the clay granulates at the earlier operation of samples preparation. (paper)