Heat and moisture transfer in freezing and thawing soils
The process of heat transmission in different kinds of ground takes place mainly by a conductive mechanism whereby thermal energy is not accompanied by transport of substance and by a convective mechanism in which heat transfer is effected by the movement of air and water in the pores of the soil. F...
| Main Authors: | , |
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| Format: | Report |
| Language: | English |
| Published: |
National Research Council of Canada
1963
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| Online Access: | https://doi.org/10.4224/20359144 https://nrc-publications.canada.ca/eng/view/ft/?id=e4f385c8-90a6-4d7c-b7ae-c106a4d9eb5c https://nrc-publications.canada.ca/eng/view/object/?id=e4f385c8-90a6-4d7c-b7ae-c106a4d9eb5c https://nrc-publications.canada.ca/fra/voir/objet/?id=e4f385c8-90a6-4d7c-b7ae-c106a4d9eb5c |
| Summary: | The process of heat transmission in different kinds of ground takes place mainly by a conductive mechanism whereby thermal energy is not accompanied by transport of substance and by a convective mechanism in which heat transfer is effected by the movement of air and water in the pores of the soil. Freezing and thawing soils are always structurally heterogeneous. Heat may be propagated through the mineral skeleton by way of conduction and also through pores where transfer takes place by conduction, convection and radiation. If the soils are water unsaturated, thermally induced moisture movement exposes special problems which can be dealt with using classical thermodynamic processes. If the soils are saturated no redistribution of water is possible. In the transitional zone between thawed and frozen zones special consideration must be given to the development of water-ice phase changes. Systems of equations have been given that allow calculation of heat and moisture transfer based on fundamentals available in the literature. The convective mechanism of heat transfer for unsaturated soils has received very little attention. The equations in this paper are a first attempt to establish general qualitative laws but no solutions are given. The way soil parameters affect the values of heat and moisture characteristics is unknown. Peer reviewed: No NRC publication: Yes |
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