Geotechnical Investigation on Compacted Clay Liner Blended with Reactive Material

Abstract

Clays are used for the construction of waste containment barriers, mainly because of its low hydraulic conductivity. In general, at several places, it may not be possible to obtain the clay satisfying the essential requirements as a liner material. Hence at many places commercially available bentonites is often used for the construction of clay liners. Bentonite undergoes significant changes in volume upon saturation. Several physical and chemical stabilization methods are in practice to stabilize the bentonite. Previous studies report that contaminants with high concentrations attack the clay minerals leading to an increase in their permeability. Exfoliated vermiculite, finds several applications in construction industry, and it is also found to be good absorbent material. Hence this study has been carried out to find the optimal percentage of vermiculite that can be added to the bentonite so that it satisfies the essential requirements of clay liners and it can also absorb the heavy metals from the contaminants. The tests for index properties and engineering properties of bentonite-vermiculite mixtures were performed. The test results show that 30% of vermiculite can be added to bentonite, so that the essential requirements of the liner can be maintained.