Geotechnical characterization of geomaterial blends with zeolitic tuffs for use as landfill liners

Abstract

Mixtures of volcanic and zeolitic tuffs from Jordan with other natural materials such as marl, sand, kaolinite and bentonite were prepared and tested for Proctor compaction in order to determine the best blend to achieve the highest dry density for use in a landfill liner. Compaction tests indicate that volcanic tuffs have higher dry densities than the zeolitic tuffs. The presence of zeolitic tuff in a mix decreases the dry density and increases the optimum moisture content. The study indicated that two mixtures of zeolitic tuff, marl, bentonite, kaolinite and sand gave the highest dry densities which, combined with the high cation exchange capacity of zeolitic tuff and bentonite, provide mixtures suitable for potential low cost landfill liners, if the shrinkage tests confirm that they are appropriate. The liquid limits measured using the cone penetration method of the volcanic tuffs were higher than those obtained using the Casagrande method except for the Rmah Tuff (RT) which showed the reverse. This needs further investigation.