Effect of moisture content on the thermal effusivity of wood cement-based composites

The influence of moisture content on the thermal effusivity of wood cement-based composite was investigated. Measurements of thermal effusivity were performed inside a closely controlled climatic cell at ambient temperature (20 +/- 0.5 degrees C) in conditions ranging from fully saturated to oven-dry. Shrotriya et al's model based on an Ohm's law approach was used for predicting the effective thermal effusivity of studied materials. The topological parameters of the model, such as sphericity of particles and resistivity formation factor, have been estimated as a first approximation from both thermal conductivity measurements and formulae proposed in the literature. Test results confirm that moisture content tends to increase the thermal effusivity significantly. It is also found that the Shrotriya et ars model yields predictions which agree quite closely with experimental data for wood aggregates-clay-cement composites for different amounts of wood aggregates and degrees of saturation.