Effect of Organic Pore Fluids on Swelling Behavior of Bentonite–Sand Mixtures

In this study, swelling behavior of bentonite–sand mixtures has been studied in presence of organic pore fluids having a wide range of dielectric constants. The organic pore fluids of different dielectric constants are prepared by mixing alcohols (methanol and ethanol) with distilled water at different proportions. A series of laboratory experiments are done to determine the free swell and oedometric swell. The free swellings of the bentonite–sand mixtures are determined as per Indian standard and the oedometric swellings are determined by using a conventional consolidometer. Efforts are given to establish the relationship between free swell and oedometric swell of the bentonite–sand mixtures. Moreover, the effects of dielectric constants of the pore fluids on the free swelling and oedometric swelling behavior of the bentonite–sand mixtures are also investigated. The results obtained from the laboratory test indicated good linear relationship between the free swell and oedometric swelling of the bentonite–sand mixtures in presence of organic pore fluids having different dielectric constants. Good linear correlations have been also observed between the dielectric constants of the pore fluids and free swell and oedometric swell of the bentonite sand mixtures.