Ata Aghaei Araei - Geotechnics Department, Road, Building and Housing Research Center (BHRC), Tehran, Iran
Amirsaeid Salamat - Geotechnics Department, Road, Building and Housing Research Center (BHRC), Tehran, Iran
Saeid Hashemi Tabatabaei - Geotechnics Department, Road, Building and Housing Research Center (BHRC), Tehran, Iran
Hossein Hassani - Geotechnics Department, Road, Building and Housing Research Center (BHRC), Tehran, Iran

This paper presents results of laboratory tests to explicate the mechanism of the Poly Vinyl Acetate (PVA) and hydrated lime on the engineering properties of the treated soil. Soil improvement is a time and cost saving method that enables unsatisfactory in-situ materials to obtaining higher strength, obviating the need for costly excavation and replacement with suitable material. Laboratory test, including consistency limits, compaction, unconfined compressive strength (UCS), and direct shear tests were carried out on treated soils. The results show that the addition of ۴% PVA and ۶% lime can improve soil properties, but lime had higher UCS on long period. Moreover, optimum percentage of PVA has a small effect on the cohesion and UCS of treated soil, but its effect on friction angle is significant.

curing, Direct Shear, lime, PVA, Unconfined Compressive