Civil Engineering Journal
Vol. 12 No. 9 (2026): September

Microstructural and Geotechnical Evaluation of Cement-Stabilized Crude Oil-Contaminated Silty Clay

Haqi H. Abbood (Department of Civil Engineering, College of Engineering, Wasit University, Wasit 52001)
Mohammed K. Hatem (Department of Civil Engineering, College of Engineering, Mustansiriyah University, Baghdad 10052)
Hasan Ali Abbas (Department of Civil Engineering, College of Engineering, Wasit University, Wasit 52001)
Nabil Al-Hakeem (Department of Civil Engineering, College of Engineering, Wasit University, Wasit 52001)
Solomon Rubay (Department of Civil Engineering, College of Engineering, Wasit University, Wasit 52001)
Mohammed Ali Hussein (Department of Civil Engineering, College of Engineering, Wasit University, Wasit 52001)
Albert Prokopov (Faculty of Civil and Industrial Engineering, Don State Technical University, Rostov-on-Don 344003)



Article Info

Publish Date
01 Sep 2026

Abstract

This study assessed the performance of Ordinary Portland Cement (OPC) in stabilizing crude oil-contaminated silty clay soil with special focus on the improvement of the geotechnical and microstructural properties. Geotechnical tests were conducted on soil samples contaminated with crude oil at concentrations up to 20% and stabilized with cement contents from 6% to 10%. The geotechnical properties investigated were void ratio, compressibility, California Bearing Ratio (CBR) and unconfined compressive strength (UCS). Furthermore, Scanning Electron Microscopy (SEM) was used to characterize the microstructure changes in the soil. The results indicated that crude oil increased the initial void ratio and compression index by 18.3% and 47.6%, respectively, and decreased the CBR by 43.1% and soil cohesion by 40%, mainly due to the lubricating effect of oil on soil particles. The addition of OPC as a stabilizing binder promoted pozzolanic reactions, which resulted in an 11–24% reduction in void ratio under an applied stress of 710 kN/m2 and a 7.7–21.5-fold increase in UCS compared with the untreated contaminated soil. SEM analysis of the soil with 10% cement showed the formation of continuous C–S–H matrices around the oil droplets, and hydraulic conductivity was decreased by about 1.5 times. The results showed that the application of OPC can significantly improve the mechanical stability and microstructure of oil-contaminated silty clay, and therefore confirm the feasibility of using it as a soil stabilizer for environmental rehabilitation.

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Journal Info

Abbrev

cej

Publisher

Subject

Civil Engineering, Building, Construction & Architecture

Description

Civil Engineering Journal is a multidisciplinary, an open-access, internationally double-blind peer -reviewed journal concerned with all aspects of civil engineering, which include but are not necessarily restricted to: Building Materials and Structures, Coastal and Harbor Engineering, ...