keywords: contaminated soil, uncontaminated soil, compaction, consistency test, California bearing ratio, Scan electron microscope
This research is an assessment of crude oil pollution on soil. The effect of crude oil pollution on engineering properties of soil was carried out in this research using laboratory experimental test methods which include: sieve analysis, Atterberg limits, compaction and California bearing ratio (CBR) tests on the samples collected. A comparative analysis based on the experimental test results obtained on the two samples of which one was collected from the oil spill affected location (contaminated soil) and the other sample is the non-oil affected soil (uncontaminated soil) to serve as control for the index and engineering properties. The results from sieve analysis and Atterberg limits tests classifies both soil samples (contaminated and uncontaminated) as Silty soil and as A-2-4 and A-2-6 soil respectively, using AASHTO specifications. The compaction test for the contaminated soil has maximum dry density (MDD) and optimum moisture content (OMC) values of 2.042 Mg/cm3 and 10.3%, while the uncontaminated soil has MDD and OMC values of 2.059 Mg/cm3 and 11.7% respectively. The CBR test result for the contaminated soil was far less than 1% (i.e., 0.27%), while that of the uncontaminated soil was 12%. The results indicated a decrease in strength, maximum dry density, optimum water content and Atterberg limits of the contaminated soil, therefore making the soil unsuitable for some Civil Engineering construction works.