Investigating the Effects of Portland Cement and Lime on Improving Glycerol-Contaminated Clay

Soil contamination through petrochemical activities and leakage of organic hydrocarbon is not just an environmental problem and also can be considered as an important geotechnical issue. Adding amendment material is one of the most suitable and economical solutions to improve the geotechnical parameters of contaminated soil. In this study, the effect of Portland cement content (3, 6 and 9%) and lime content (10, 20 and 30%) on kaolinite clay contaminated with glycerol content (3, 6 and 9%) was investigated through an experimental program. For this purpose, the samples were prepared as mixtures of clean or glycerol-contaminated clay with different Portland cement and lime contents for 7 days curing time. Then, unconfined compressive strength (UCS) tests were conducted on the samples. The results showed a reduction of the strength of glycerol-contaminated kaolinite clay. The strength reduction increased with increase in degree of contamination. Based on the scanning electron microscopy (SEM) analysis, it was found that the presence of glycerol prevents the interaction between soil-cement particles. However, adding Portland cement and lime to uncontaminated and contaminated soil increased the strength. The rate of increase in UCS increased with Portland cement and lime content. Also, the results of soil improvement showed that the strength of soil-cement mixture containing 9% Portland cement is approximately equal to that of the soil mixed with 10% lime. In other contents, the degree of improvement was dependent to the applied cement content. The main reasons were polar behavior of glycerol and its dielectric constant. The results were also analyzed and proved using the images taken by SEM.