Journal Published Online: 26 May 2022
Volume 50, Issue 6

Impacts of Pre-contamination Moisture Content on Mechanical Properties of High-Plasticity Clay Contaminated with Used Engine Oil



The oil contamination of soils and the remediation techniques to enhance the engineering properties of the ground have been an emerging challenge in the geoenvironmental field. While several studies were conducted to examine the behavior of the contaminated granular soils, little is known about the mechanical properties of the oil-contaminated clays. This paper investigates the impacts of the in situ pre-contamination moisture content (PMC) on the behavior of fine-grained soil contaminated with various levels of used engine oil. Extensive laboratory experiments were performed on sandy clay with different initial moisture conditions and various amounts of used engine oil varying from 0 to 16 %. The experimental results, including the Atterberg limits, linear shrinkage (LS), unconfined compressive strength, shear strength, and small-strain shear modulus in conjunction with microstructural image analysis, were reported and discussed. It is observed that when oil content was increased, both LS and plastic limit (PL) increased while the liquid limit decreased in the contaminated soil. Moreover, the inclusion of engine oil contributed to the reduction in the plasticity index, which was also impacted by the PMC of the soil. An increment in the PL was correlated with a significant decrease in shear strength, shear modulus, and other associated parameters such as friction angle and cohesion. In agreement with the results, a broader range of elasticity and improved stability at the microstructure level was associated with a lower pre-contamination water content (PMC). Overall, this paper shows that knowledge of site moisture levels before contamination is essential to evaluate the implications of contamination by used engine oil.

Author Information

Omar, Khalid Riyadh
School of Civil and Environmental Engineering, University of Technology Sydney (UTS), Ultimo, NSW, Australia
Fatahi, Behzad
School of Civil and Environmental Engineering, University of Technology, NSW, Australia
Nguyen, Lam Dinh
School of Civil and Environmental Engineering, University of Technology Sydney (UTS), Ultimo, NSW, Australia
Pages: 27
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Stock #: JTE20210477
ISSN: 0090-3973
DOI: 10.1520/JTE20210477