The determination of thermal conductivity / thermal resistivity of backfill materials for cable trenches and geothermal applications as a function of water content and compaction is a major focus of our services.

We provide the necessary information to compare and select suitable backfills and to improve the thermal properties of a given material.

Backfill Materials

Cable trenches and geothermal installations usually require backfills with low thermal resistivity / high thermal conductivity. Like sand and soil in general, backfills consist of solid grains (matrix) and pore volume. A good backfill is characterized by a high matrix thermal conductivity and a low pore volume (i.e. a high degree of compaction). Thermal conductivity tests help to select an appropriate material for your application.

Dry-Out Curves

Thermal conductivity vs. moisture content A dry-out curve covers a material's entire thermal resistivity range: A saturated sample is dried in 5-10 steps until the weight becomes constant. The thermal resistivity is determined in each of these steps and plotted versus the water content.

Our Services

We provide measurements at any desired water content (dry, saturated, field moisture) or complete dry-out curves. Results are reported as thermal conductivities in W/mK or thermal resistivities in mK/W.