an investigation on the effects of adding nano-sio2 particles and silica fume with different specific surface areas on the physical and mechanical parameters of soil-cement materials

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 makes a dense and durable composition with low permeability and abrasion resistant. since most of the recent researches are focused on the addition of nano-sio2 on concrete, in this paper it has been attempted to use nano-sio2 particles in soilcement and observe the effects. due to the fact that in concrete there are no particles passing sieve 200 and this restriction does not apply to soilcements, some tests were carried out on the nano-sio2 + soilcement matrix because of the meaningful difference between concrete and soilcement. the test procedure consists of moisturedry density, unconfined compressive test and hydraulic conductivity. in these tests, silica fume (with specific surface area of 21 m^2/g), nano-sio2 (with specific surface area of 200 and 380 m^2/g) were added to soilcement. the results show that adding certain amounts of nano-sio2 particles to the soilcement matrix can improve the compressive strength and reduce permeability and speed hydration reactions in the matrix in presence of nano-sio2 particles.