The Effect of SSR400 Solution on Engineering Properties of Subgrade in Asphalt Pavements

In this paper, effect of a stabilizing material known as "SSR400 solution", which is obtained from briny waters of Iran's central desert and is rich in calcium chloride and magnesium chloride, on improving the strength and swelling of fine-grained soil (containing silt and clay) in asphalt pavements is investigated. For this purpose, soil samples were taken from various secondary roads in Sistan region, Iran, and by selecting different amounts of SSR400 solution (12.5 to 22.5 percent), some test samples were prepared using standard methods, and they were tested for density, moisture content, California bearing ratio (CBR), unconfined compressive strength (UC), and Atterberg limits (liquid limit and plastic limit). Results showed that using SSR400 solution as a stabilizing material increases bearing capacity of silty and clayey soils, but is not effective in controlling the soil swelling. Moreover, the optimal amount of this solution for mixing with silty and clayey soils was 16.5 and 14.5 percent, respectively.