Iranian (Iranica) Journal of Energy and Environment 14(4): 353-360, 2023 Please cite this article as: J. E. Sani, T. S. Ijimdiya, G. Moses, A. A. Lawal, 2023. Use of an Eletrokinetic Remediated Soil as a Road Subgrade Material, Iranian (Iranica) Journal of Energy and Environment, 14(4), pp. 353-360. Doi: 10.5829/ijee.2023.14.04.05 Iranian (Iranica) Journal of Energy & Environment Journal Homepage: www.ijee.net IJEE an official peer review journal of Babol Noshirvani University of Technology, ISSN:2079-2115 Use of an Eletrokinetic Remediated Soil as a Road Subgrade Material J. E. Sani 1 *, T. S. Ijimdiya 2 , G. Moses 1 , A. A. Lawal 1 1 Department of Civil Engineering, Nigerian Defence Academy, Kaduna, Nigeria 2 Department of Civil Engineering, Ahmadu Bello University, Zaria, Nigeria PAPER INFO Paper history: Received 22 February 2023 Accepted in revised form 19 April 2023 Keywords: Atterberg limit California bearing ratio Crude oil contaminated soil Electrokinetic remediated soil Subgrade Unconfined compression strength ABSTRACT The soil investigated for suitability checks, as a subgrade material in this study, was a crude oil contaminated (COC) soil treated using an electrokinetic technique. The index properties and compaction characteristics of the electrokinetic remediated (EKR) soil are natural moisture content was 10.97%; The Atterberg limit test showed liquid limit, plastic limit, plasticity index and linear shrinkage of 36.50%, 22.05%,14.45 %, and 4.30%, respectively. The percentage of 62.80% passes 0.075mm sieve with a maximum dry density (MDD) of 1.77 Mg/m 3 , and the moisture content decreased from 13.2% to 11.81%. The soil is classified as A-6 according to AASHTO classification system and belong to clay of low plasticity CL or OL group according to the Unified Soil Classification System. The unconfined compression strength, (UCS), durability, and California bearing ratio (CBR) of the electrokinetic remediated soil improved marginally from 46.63kN/m 2 to 92.64kN/m 2 ; from 18% to 23%; and from 2.55% to 4.05% respectively. However, these results obtained, do not meet the minimum requirement of the Nigerian General Specification. As a result, it is advised for further research, that an EKR soil be stabilized using cement stabilization to achieve the desired subgrade strength. doi: 10.5829/ijee.2023.14.04.05 INTRODUCTION 1 In past decades, there have been a progressive increase in the use of an electrokinetic technology for the recovery of a polluted or contaminated soil. Though little or not much work have been carried out on the geotechnical engineering properties of an electrokinetic remediated soil to know their suitability or the needs for improvement that might be required on the material. Electrokinetic (EK) remediation still a new technology used in soil remediation in polluted soils that has low permeability [1–6]. Recently, many works have been done by researchers with a positive breakthrough by the application or combination of enhancement method to improve the degree or quality of remediation. It involves the application of low electric voltage to an electrokinetic cell containing two or a couple of electrodes inserted in an electrolyte at both ends of the cell to remove, organic, *Corresponding Author Email: jesani@nda.edu.ng (J. E. Sani) inorganic, and heavy metal compounds from a contaminated soil [2, 5, 7, 8]. EKR achieves the purpose of remediation by applying an electric field to the contaminated soil/sediment, enriching the pollutants to the cathode or anode zone through electroosmosis, electromigration, and electrophoresis (Figure 1). Electric migration is the movement of charged dissolved ions through an aqueous medium toward the electrode with a polarity opposite the ion charge [9]. Electro-osmosis is the movement of pore fluid and dissolved constituents within a porous medium that typically occurs between the anode and cathode, because of the negative charge characteristic of the soil particle surface [10]. However, the change of surface charge of soil may change the direction of electroosmosis. Electrophoresis refers to the transport of charged particles or colloids in soil under the action of an electric field. Soil organic matter, microbial cells, and small soil