Effect of Freeze–Thaw Cycles on the Strength of a Nanosilica and Lime Treated Clay

In this study, the unconfined compressive strength of a clay treated with nanosilica and lime was investigated under freeze–thaw conditions. The specimens were prepared at their corresponding optimum water contents and compacted under a standard Proctor compactive effort. The pure clay and the clay treated with 5% lime were subjected to freeze–thaw cycles to determine the strength changes of specimens. The maximum number of cycles applied to the specimens was 10. The cycles were applied in 12 h intervals and the temperature range was ±18 °C. Subsequently, the clay was treated with 0.3, 0.5, 0.7 and 1% nanosilica and 5% lime. The clay specimens showed a tendency to decrease in strength as a result of freeze–thaw cycles. The maximum strength loss observed was around 41%. It was concluded that, it was not possible to achieve sufficient amount of improvement by using solely nanosilica in the clay specimens. The unconfined compressive strength of nanosilica and lime treated clay accelerated with curing time. Besides, the strength loss of specimens due to freeze–thaw cycles could be partially prevented with the addition of nanosilica and lime. Consequently, usage of nanosilica together with lime, resulted in a better improvement, even if the soil was subjected to freeze–thaw cycles.