Geotechnical Properties and Microstructure of Liquid Polymer Amended Fine-Grained Soils

The paper presents the effect of liquid polymer on the geotechnical properties and microstructure of two fine-grained soil. Commercially available liquid polymer was used to stabilize a commercially available soil (Soil I, type ML) and natural soil (Soil II, type CH). Various physical properties test has been conducted to characterize the soils. The liquid polymer was mixed at various percentages (i.e. 2, 3, 4, and 5%) on dry weight basis. The polymer-stabilized soil samples were cured for 7, 14, and 28 days under confined and open-air environment. Unconfined Compressive Strength (UCS) test and California Bearing Ratio (CBR) test were conducted to evaluate the strength of polymer-stabilized soil. The results show that with the addition of polymer; UCS value for ML samples prepared at its OMC increases up to 75% in open-air environment and up to 14% in confined air environment. CH soil samples prepared at its OMC shows cracks while curing in open-air environment and there is no significant change of strength in confined air environment. For CH soil UCS samples were prepared with reduced moisture contents and cured in open air environment shows increase in UCS strength up to 10%. CBR test results shows that there was marginal increase (i.e. 14%) in CBR value for CH soil but a significant increase (i.e. 340%) in CBR value for ML soil. X-ray diffraction test was conducted for ML and CH to determine the mineralogical composition of virgin and liquid polymer-stabilized soil. It was observed that, no new minerals were formed with the addition of polymer. Scanning electron microscope test was also conducted to analyze the microstructure of the virgin and polymer-stabilized soils.