Characteristics and empirical formula of electrical resistivity of cement-solidified lead-contaminated soils

In order to explore the application potential of electrical resistivity method in the field of solidified heavy metal-contaminated soils, the artificial contaminated soils with five different lead contents are solidified using cement, and then their electrical resistivities and unconfined compressive strengths after various curing periods are tested. The relationship between the electrical resistivity and unconfined compressive strength is discussed. The test results show that the cement hydration reaction results in an increase of the electrical resistivity of solidified samples, but the electrical resistivity decreases with the increase of after-curing porosity, degree of saturation and lead content. A key parameter (n_t·)/ (a_w·T^0.5) (e is the Euler’s number) is proposed to comprehensively reflect the effects of the lead content, cement hydration reaction and dense state of soils on the electrical resistivity of solidified soils. The Archie’s electrical resistivity formula is extended to solidified heavy metal-contaminated soils by replacing the porosity by the key parameter. There is a power function relationship between the strength and the electrical resistivity while the lead content of solidified soils is certain. The electrical resistivity method can be used as a non-destructive, economical and continuous way to evaluate the quality of solidified heavy metal-contaminated soils.