Improving the Geotechnical Properties of Non-Cohesive Soils Using Portland Cement and Some Composite Polymers in a Selected Location in Umm Qasr City, Basrah Governorate, Southern Iraq

In this study, non-cohesive soils from a site in the city of Umm Qasr in Basrah Governorate, southern Iraq, are improved by adding Portland cement at a rate of 5% of the sample's weight and a polymeric mixture that included thinner as a solvent, polyvinyl acetate, unsaturated polyester, and isocyanides in proportions of 5, 10, 15, 20, and 25% of the added cement's weight through the use of geotechnical tests that include the degree of improvement in the soil's geotechnical properties, such as compaction, direct shear strength, California Bearing Ratio, and absorption, to ascertain the optimal percentage of polymer that is beneficial for improvement. The results show that the optimal moisture content values decrease from 10% to 9%, the maximum dry density values increase from 1.982 g/cm3 to 2.162 g/cm3, and the absorption values decrease from 28.7% to 9.6%. The addition of polymers and cement serves as a binding agent, the angle of internal friction increases from 27 to 32 degrees, and fosters the development of cohesion between the soil particles to (43.14 kPa). The California Bearing Ratio value increases from 27% to 54% by adding polymer at a rate of 20% of the cement weight and cement at a rate of 5% of the sample weight.