- Author
- Salomone, L. A. | Yokel, F. Y. | Wechsler, H.
- Title
- Influence of Soil Type and Gradation on the Thermal Resistivity of Soils.
- Coporate
- National Bureau of Standards, Washington, DC
- Report
- NBSIR 84-2935, October 1984,
- Distribution
- Available from National Technical Information Service
- Keywords
- thermal conductivity; soil tests; thermal measuring instruments; soil compacting; soil water; sands; clay soils; silts; moisture content; heat transfer; tables (data); graphs (charts) | thermal conductivity | sand
- Abstract
- Laboratory thermal probe tests performed on four (4) different soils were used to study the influence of soil type and gradation on the thermal resistivity of soils. The four soils covered a wide range of gradations and included: two sands (SP and SP-SM), a silty clay (CL), and a silt (ML). Results are presented which indicate that as the sand content increases in a silty clay (CL), the minimum thermal resistivity and the critical moisture content decrease for the range of compactive efforts studied. Increasing the medium and coarse sand fraction in a granular soil significantly increases the heat conductive properties of the soils. Also, in the stable region of each of the major soil groups (i.e. granular and fine-grained soils), the influence of soil type and density on the thermal resistivity of soils is negligible and a constant value of thermal resistivity is observed. The constant value of thermal resistivity is approximately 30 to 40C cm/watt and 50 to 70C cm/watt for granular soils and fine-grained soils, respectively.