Stabilisation of clay soil with polymers through electrokinetic technique

Abstract

In this work, the effect of migration of two polymers, namely polyethylene oxide (PEO) and sodium carboxymethyle cellulose (CMC) with concentrations of 2, 4 and 6 g/L on improvement of a clay soil, is investigated through a program of experimental tests. The tests were conducted in a special apparatus under the voltage of 50 V and over a period of 7 days. During each test, the values of pH and EC in the two reservoirs, discharge fluid from the cathode reservoir were measured at different time intervals. At the end of each test, the strength of soil was measured across the length of sample. SEM tests were also carried out at the end of the test on the samples. The results showed that both polymers caused significant increase in the settlement and undrained shear strength of the soil but the maximum strength was obtained at a concentration of 4 g/L. At this concentration, the values pH and EC at the cathode reservoir were about 13 and 48 dS/m for both polymers. The SEM results revealed that the increase in strength is due to the covering of the particle surfaces and penetration of the polymer between the spaces of soil particles.