Effect of void ratio on swelling and permeability of bentonite

A series of experiments has been conducted at the Geosphere Research Institute of Saitama University, Japan to evaluate the effect of void ratio on swelling and permeability of bentonite. Void ratio is the prime criterion for swelling and permeability of bentonite and bentonite-sand mixtures when it is used as a buffer material for waste disposal facilities. At the end of swelling void ratio increased 7 to 8 times when compared with the initial state of the bentonite and bentonite-sand mixture. Permeability is also increased as a result of an increase in void ratio.