The effect of freeze-thaw cycles on mechanical properties of fine-grained soil modified by cement and nanocement

Freeze-thaw (F-T) cycles cause substantial detriment to geotechnical structures, especially roads, every year. Recently, researchers have increasingly used nanomaterials to improve soil resilience. This study evaluated the effect of soil stabilization by cement and nanocement on resistance changes subjected to F-Tcycles.For this purpose, clayey soil was combined with 1, 2, 3, and 4% stabilizers based on dry unit weight. Atterberg limits and standard compaction tests were performed on the prepared mixtures. The results showedthat increasing the stabilizers enhanced the optimum moisture content, liqid limit, and plastic limitwhile decreasingthe maximum dry density and plastic limit. Then, the cylindrical specimens of the pure and stabilized soilswere prepared and curedwithin 42 days. Finally, unconfined compressive strength(UCS) tests were conducted on the samples after applying zero, three, six, and nineF-T cycles. UCSin the stabilized soil increased to a value about12 times thatin the pure soil. The UCSvalue was reduced on average to 49%inthe pure soil specimens by applying nine F-T cycles, whichfurther decreased on averageto 36% and 31%after adding cement and nanocement, respectively. However, the lowest UCS value was observed in the stabilized soil specimens, reaching 26% and 19%in 42 daysafter applying nineF-T cyclesand adding 4% cement and nanocement, respectively.