Hardening of clayey soil blocks during freezing and thawing cycles

摘要

Considering the lack of references dealing with the behaviour of clayey soil blocks subjected to freezing-thawing cycles, exploratory work has been carried out on such blocks to study the effects of freezing-thawing cycles on their mechanical properties. As the blocks were not stabilized, the procedures conventionally applied for freezing-thawing cycles, in which the samples are immersed, were adapted to this case of study: the specimens were humidified by placing them in a moist environment for 1 week (20 ℃ and 95% RH (relative humidity)) and were then subjected to freezing-thawing cycles without any re-humidification between cycles. The variations of weight and compressive wave velocity showed that freezing-thawing cycles led to the desiccation of the samples. The consequences of these cycles on the characteristics of the soil blocks were thus those of a conventional desiccation of specimens and, in particular, their hardening. This hardening was highlighted by the study of the mechanical characteristics of the clayey soil blocks (compressive strength and modulus).