Freeze–thaw performance of clayey soil reinforced with geotextile layer

In cold climates, freeze–thaw cycling is an important issue in engineering. In freeze cycles, translocation of water and ice that can be caused by thermodynamic conditions at temperatures just below 0 °C, changes engineering properties of soils. In previous studies, changes in physical, chemical and mechanical properties of soils were investigated. In this study, UU Triaxial compressive tests have been performed to investigate the effect of freeze–thaw cycles on strength properties of soil reinforced with geotextile layer. A clayey soil, reinforced with a geotextile layer located at mid-height of the sample, was compacted in the laboratory and subjected to a maximum of 9 closed-system freeze–thaw cycles. Computerized tomography (CT) images have also been taken from samples. It was found that for the investigated soil, unconsolidated undrained triaxial compressive strength of unreinforced soil decreased with increasing the number of freeze–thaw cycles, whereas reinforced samples showed better performance and the strength reduction amount decreased from 43% to 14% by reinforcing the soil. CT images have shown that free water moved through the soil particles toward the lower part of the soil samples. In addition, it was found that sample reinforcement can reduce the effect of freeze–thaw cycles on changes of cohesion and resilient modulus of the soil.

► A clayey soil was reinforced by a nonwoven geotextile layer at mid-height of the sample.
► The pure and reinforced samples were affected by 0–9 freeze–thaw cycles.
► Freeze–thaw cycles reduce the triaxial strength of all reinforced and unreinforced soil samples.
► Existence of a nonwoven geotextile reduces the freeze–thaw influence and leads the free water to the deeper part of the soil.
► This phenomenon was proved by CT images and CT values of frozen pure and reinforced soils.