Effects of light crude oil contamination on the physical and mechanical properties of fine sand

The use of oil-contaminated sand in building and construction is now being considered as an alternative and cost-effective way to minimize its adverse effect on the environment. To achieve this, the effect of oil contamination on the important mechanical properties of sand should be investigated first. This study investigated the effect of petroleum-derived contaminants on the water absorption, permeability, cohesion, friction angle, and shear strength of fine sand. Contaminated samples were prepared by mixing fine sand with different percentages of light crude oil (0 to 20%). The results indicated that the water absorption of fine sand decreases with an increase in crude oil. An increase in the cohesion was observed for sand with up to 1% of oil contamination, after which the cohesion began to decrease, which also results in the reduction in the permeability. A slight reduction in the friction angle was found for oil-contaminated fine sand. At a low normal stress of 50 kPa, as the percentage of light crude oil increased, the shear strength increased up to 1% of oil contamination and then it decreased. These results provided useful information on how oil-contaminated sand can be used safely and effectively in building and construction.