Thermal conductivity measurements of coarse-grained gravel materials using a hollow cylindrical sensor

摘要

We report on new results for the thermal conductivity of granular materials, in particular large-grained gravels. For these measurements, a cylindrical-shaped heated sensor was developed and used, which allows to include gravels with grain sizes in the several centimeter size range into the investigation. Such materials are, among else, important as construction materials for road and railway embankments. Measurements were done at different gas pressure levels (from normal atmospheric level down to the millibar range) and for dry and wet conditions. The results of the low pressure measurements may become relevant in view of possible applications on other planetary bodies, like at the surface of the planet Mars, which will be explored in the coming decade by in situ geotechnical methods.