Milad Tajdini - Ph.D. Geotechnical Engineering,
Maryam Dorfaki - Bs.C. Islamic Azad University Roodehen.
Soheil Esmaili Dorani - Ms.C. Islamic Azad University Sciences and Researches branch

Soil cement is a mixture of Portland cement, soil and water, in which hydration of cement and compaction causes the materials’ constituents to bond together making a dense and durable composition with low permeability and abrasion resistant. Since most of the recent researches are focused on the addition of nano-SiO۲ on concrete, in this paper it has been attempted to use nano-SiO۲ particles in soil-cement and observe the effects. Due to the fact that in concrete there are no particles passing sieve ۲۰۰ and this restriction does not apply to soil-cements, some tests were carried out on the nano-SiO۲ + soil-cement matrix because of the meaningful difference between concrete and soil-cement. The test procedure consists of moisture-dry density. In these tests, silica fume (with specific surface area of ۲۱ m۲/g), nano-SiO۲ (with specific surface area of ۲۰۰ and ۳۸۰ m۲/g) were added to soil-cement. The results show that adding certain amounts of nano-SiO۲ particles to the soil-cement with silica products can improve the unconfined compression strength of soil cement.

Soil-cement, Silica Products, Unconfined Compression Strength, Nano-SiO۲.