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

Abstract

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 nanocement and cement on resistance changes subjected to F-T cycles. 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 showed that increasing the stabilizers enhanced the optimal moisture content, liqid limit, as well plastic limit while decreasing the maximum dry density and plastic limit. Then, the cylindrical specimens of the pure and stabilized soilswere prepared and cured within 42 days. Finally, unconfined compressive strength (UCS) tests were performed on the specimens after applying zero, three, six, and nine F-T cycles. UCS in the stabilized soil increased to a value about 12 times that in the pure soil. The UCS value was reduced on average to 49% in the pure soil specimens by applying nine F-T cycles, which further decreased on average to 36% and 31% after adding cement and nanocement, respectively.