ELECTRICAL RESISTIVITY AND STRENGTH PROPERTIES OF SODIUM SULFATE-CONTAMINATED SOIL SOLIDIFIED WITH CEMENT

A common method to stabilize and solidify contaminated soil is to use a cement binder. To predict the unconfined compression strength of such treated soil, we developed a prediction formula. For testing, five different contents of sodium sulfate solutions mixed with silt and ordinary Portland cement were selected as basic materials to make cemented soil blocks. Electrical resistivity under different current frequencies and unconfined compressive strengths were measured after curing the blocks for 3, 7, 14, 28, 60, and 90 d. Results show that AC electrical resistivity decreases with an increase in current frequency at all content values. Strength and electrical resistivity increase logarithmically with increasing age. With an increase in content, strength varies with parabolic function and electrical resistivity decreases exponentially. The strength prediction formula was established according to the linear relation between strength and electrical resistivity. Based on the degree of influence of sodium sulfate on the strength of cemented soil, an evaluation standard of electrical resistivity was established.