Compaction and volumetric shrinkage of bentonitic mixtures

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.