CHEMICAL ASPECTS OF SOIL FREEZING

Abstract

Abstract : Soil water chemistry and soil particle characteristics directly and significantly influence the freezing process in soils. The rate of frost heave is influenced because chemicals modify water migration and depress the freezing point in soils. Solutes are concentrated when they are expelled from crystallizing ice, modifying adsorbed film thicknesses, depressing freezing points, creating concentration gradients, altering forces between particles or between ice particles, and modifying the chemical potential of the water. These effects often have counteracting influences on frost heave. Solute expulsion during freezing produces a 'fringe-like' freezing front in saline soils, primarily because of freezing point depression; this may also be true in 'non- saline' soils. Heave can be reduced by adding chemicals to soil to depress the freezing point to modify the soil's structure or hydraulic characteristics. The concentration of solutes in the unfrozen water of the freezing soil can possibly be used for isolating toxic wastes in soil. Ground freezing, Soils, Soil chemistry, Soil freezing.