Procedure for Determining the Segregation Potential of Freezing Soils
Basic frost heave data obtained from various types of laboratory freezing tests, using computerized ramp temperature generation and temperature control at both warm and cold ends of a soil specimen, are analyzed to determine the segregation potential. Automatic volume change measurements provide fair values of cumulative water intake, but not accurate water intake rates. A method based on accurate measurements of total heave, taking into account the amount of heave from in-situ freezing of pore-water, yields relevant freezing characteristics of soils. Precise and automatic acquisition of temperature measurements and of total heave during an open-system freezing test enables accurate definition of the segregation potential, the suction at the frozen-unfrozen interface and the rate of cooling of the frozen fringe, immediately after testing. Examples of freezing test results are given to emphasize the influence of various factors such as the temperature at the segregation-freezing front, the soils porosity, and the unfrozen water content on the segregation potential of freezing soils.