Simple determination of the thermal conductivity of the solid phase of particulate materials

It is often desirable to predict the thermal conductivity of a heterogeneous or composite material based on its composition, particularly where variations in composition are expected. In the case of particulate materials such as sand and soil the volume fraction of the solid phase is often known, while itʹs thermal conductivity is not (and vice versa for the fluid phases). It is proposed that the thermal conductivity of the solid phase of granular materials may be determined simply by measuring the thermal conductivities of the material in both the bone-dry and water-saturated states and making use of a modified form of Maxwellʹs conductivity model. The method was illustrated using beach sand.