Electrical conductivity of sand–clay mixtures

This paper presents the results of the electrical conductivity measurements of sand–clay mixtures that were formed of three types of sands and five pure clays and prepared with water of low salinity. The results show that an increase in clay content results in an increase in the overall electrical conductivity. Moreover, a direct or inverse relationship between the overall soil electrical conductivity (σ T ) and porosity (n) is observed depending on whether the water conductivity (σ w ) is higher or lower than the clay particle surface conductivity (σ s ). Common predictive models for electrical conductivity were developed for sands and clayey sands with a clay content of less than 20%. This research extended these studies to include clays, sandy clays and clayey sands to show that it is possible to predict the electrical conductivity of a soil from its composition and fabric.