Abstract

This study presents an attempt of experimental study on the effect of adding asphalt emulsion and Portland cement on the engineering properties of sand poorly graded river soil used as subgrade soil in pavement construction. The soil brought from sides of Al-Kufa River in Najaf state middle west of Iraq. Asphalt emulsion used in this study is that manufactured for surfacing and cold paving proposes. While Portland cement is that used in construction building. Percent of adding are (0, 3, 6, 9, 12 and 15) % by weight. Properties of soil studied and presented in this paper are compaction, optimum water content, CBR, and direct shear. Results showed that the adding of asphalt emulsion and cement increase the dry density in different rate. While the optimum water content decrease with increasing asphalt emulsion and increase with increasing cement added. Direct shear of soil stabilized with cement is higher than both natural soil and that stabilized with asphalt emulsion. CBR values showed the same trend of direct shear test results.