Influence of freezing mode on frost heave characteristics

Step-freezing and ramped-freezing tests were conducted on samples using a clayey silt passing the 100 sieve with a clay size content of 29% by weight in order to emphasize the influence of various factors such as the rate of cooling, the suction at the frost front and the freezing path. The trends observed in each type of freezing test can be explained using the mechanism of ice lens formation based on changes in the characteristics of the frozen fringe during transient freezing proposed by Konrad and Morgenstern (1980). The experimental program also showed that total heave did not systematically reflect the influence of the various factors but that a consistent trend was obtained when the freezing tests were analysed in terms of the segregation potential, SP. Furthermore, similar values of SP were obtained for small cooling rates independently of the type of freezing.