Compaction and volumetric shrinkage of bentonitic mixtures

Abstract

This study presents compaction and volumetric shrinkage results for zeolite–bentonite mixtures and sand–bentonite mixtures in terms of bentonite content, zeolite particle size and mixture type. Based on the results obtained, the zeolite–bentonite mixtures had significantly lower dry unit weights and higher compaction water contents than those of the sand–bentonite mixtures. The volumetric shrinkage strains of bentonitic mixtures changed only slightly up to 30% bentonite content, but increased considerably when 50% bentonite content was used in the mixtures. The effect of zeolite particle size on the volumetric shrinkage of zeolite–bentonite mixtures was also determined. The measurements showed that the zeolite–bentonite mixtures prepared with fine zeolite were able to shrink more than those prepared with granular zeolite. However, there were comparable volumetric shrinkage strains between granular zeolite–bentonite mixtures and sand–bentonite mixtures. Two-way analysis of variance was conducted to evaluate whether zeolite particle size, bentonite content and mixture type have statistically significant effects on the volume shrinkage strains of bentonitic mixtures.