Laboratory study on the effect of leachate type to swelling behavior of bentonite

Abstract

Bentonite is well known as highly plastic, swelling clay material, the product of volcanic ash. An experimental test of the effect of leachate type on swelling behavior of bentonite has been conducted. Four types of liquids, tap water, 10 g/l of NaCl solution, 11.1 g/l of CaCl2 solution, and 100 ml/l of ethanol solution were used in the tests. Liquid limit, plastic limit, free swelling index, and swelling pressure tests were carried out to evaluate the relative swelling ability of bentonite when interacted with different leachate types. The result of free swelling tests indicated bentonite swelled higher when interacted with tap water and ethanol solution compare with NaCl solution and CaCl2 solution as a liquid. The value of liquid limit and plastic limit of bentonite for ethanol solution and CaCl2 solution were highest and lowest among liquid tested, respectively. The result also showed that bentonite has the highest swelling pressure when contacted with tap water but opposite for NaCl solution.