Evaluation of the influence of salt concentration on cement stabilized clay by electrical resistivity measurement method

• The higher the salt concentration, the lower the strength of stabilized clay.
• Strength is proportional to electrical resistivity of stabilized clay.
• Electrical resistivity method can evaluate quality of cement stabilized clay.

The influence of salt concentration on the cementation process of cement stabilized clay is studied using the electrical resistivity measurement. The clay with various sodium chloride salt concentrations was prepared artificially and stabilized by Ordinary Portland cement with different contents. A series of electrical resistivity tests and unconfined compressive strength tests of cement stabilized clay specimen after curing for 28 days were carried out. The electrical conductivity and pH value of pore fluid of the cement stabilized clay were also measured, and the microstructure of the samples was investigated by a scanning electron microscope. The results indicate that a high salt concentration has a detrimental effect on the unconfined compression strength of cement stabilized clay and results in a low electrical resistivity. A good linear relationship between the unconfined compression strength and the electrical resistivity of cement stabilized clay was observed. A unique exponential func'tion well adapts electrical resistivity values with cement content and salt concentration. The porosity-salt concentration/cement content ratio is an appropriate parameter to assess the electrical resistivity of the cement treated salt-rich soil investigated. The electrical resistivity measurement can be used as a non-destructive and both time and cost effective method to evaluate the quality of cement stabilized soft clays in practice.