IMPROVEMENT OF GEOTECHNICAL PROPERTIES OF EXPANSIVE SOILS USING CEMENT

Expansive soils are distributed in many regions in world. (including Iraq),particularly in semiarid regions with alternating wet and dry seasons. Therefore, it is necessary to study the geotechnical properties of such soils due to the possible large damage of structures founded and constructed on this soil. The soil used in this research is from Abu-Ghreab site.This paper reports the outcome of an investigation into the effect of cement on geotechnical properties of expansive soil, to ascertain its suitability for use as a modifier or stabilizer in the treatment of the soil. Classification, consistency indices, specific gravity, compaction, direct shear, and swell percentage and swell pressure tests, were conducted on specimens of expansive soil. Results of tests showed that the soil was a CH soil, according to the USCSclassification system.Liquid limit , plastic limit and plasticity index are reduced by adding 8% of cement , at optimum moisture content the maximum dry density value increase with increase the percentage of cement adding to the expensive soil and conducting direct shear test, an obvious increase is noticed in the amounts of cohesion (C) and internal friction angle (Ø) .While swell percentage decreases by adding cement and while the swell pressure decreases to the half of its original values.