Research
| Title： | Evaluation of electrical resistivity of lead-contaminated soils stabilized by electrolytic manganese residue-based binder |
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| First author： | Tu, Chaoliu; Li, Yuan; Wang, Chen; Liu, Lei; Zhang, Yi |
| Journal： | JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING |
| Years： | 2025 |
| DOI： | 10.1016/j.jrmge.2024.12.010 |
| Abstract： | Evaluating the stabilized lead (Pb)-contaminated soils through sampling and laboratory testing involves costly and time-consuming processes. Therefore, this study employed a low-cost and non-destructive resistivity tool to evaluate the Pb-contaminated soils stabilized by electrolytic manganese residue (EMR)-based geopolymer (EG-OPC) from the strength and environmental benefits perspective. First, unconfined compressive strength (UCS) and leaching tests were conducted to study the stabilization effectiveness of EG-OPC. Results indicated that the UCS values of soil (5000 mg/kg of pollutants) stabilized by 20% EG-OPC were 4.87 MPa and 8.13 MPa after 7 d and 60 d of curing, respectively. After 60 d of curing, the Pb concentration in the leachate reached 44 mg/L, far lower than the control group (321 mg/L). Second, soil, pore water, and leachate resistivity (ERS, ERW, and ERL) were measured to establish fitting relationships with strength parameters and pollution risk. The good fitting results (e.g. ERS/ERW versus UCS/secant modulus (E50): correlation coefficient R-2 approximate to 0.9, ERS/ERW versus Pb contents: R-2 approximate to 0.9, and ERL versus Pb2+ concentration: R-2 = 0.92) and well used Archie's law (ERS versus ERW: R-2 > 0.9) indicate that the resistivity can be used to evaluate the stabilization effectiveness. Furthermore, the microscopic results revealed two behaviors, demonstrating the reliability of resistivity: (1) with the hydration process, resistivity increases due to a denser structure and lower amounts of free water and Pb ions, and (2) the addition of Pb reduces resistivity due to its inhibition or even destructive effects on cementation and formation of hydration products. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/). |
