LAUSR

Understanding the effects of freezing and thawing on base soil and filling materials is critical for construction stabilisation and environmental considerations. We have examined the effects of freezing and thawing on the physico-mechanical behaviours of clayey soils. A total of 64 moulded samples of high plasticity clay (CH) and clayey sand (SC) soils were prepared with regular water contents to reflect the moisture conditions of the active surface layer. Soil samples for all tests were put into a freezer at a temperature of − 18 °C for 24 h. Samples were then removed and placed in a cabinet with a temperature of 21 °C and 80% relative humidity for 24 h. Freeze–thaw (FT) sequences were conducted with 1, 3, 7, 14 and 21 of these FT cycles. The plastic and liquid limits of the samples decreased abruptly after the first FT period. The classification of the clayey sand according to the Unified Soil Classification System was modified from “SC” to “SM” silty sand after the first FT cycle. Furthermore, the coefficient of consolidation of the CH soil increased after the third FT cycle, and these values for SC began to grow after the first FT period. Cohesion decreased by about 38.54%, and the internal friction angle increased by about 36.99% for the CH soil, whereas the cohesion and the internal friction angle of the SC soil decreased by approximately 95.90 and 25.44%, respectively, after the FT tests.