Geotechnical Characteristic of Compacted Sand Bentonite Mixture

Abstract

Sand and bentonite mixture is generally used as a liner or backfill material at waste disposal sites and construction of hydraulic barriers. Bentonite is added to sand to achieve a higher compaction density and lower shrinkage. Permeability and strength are important properties of sand-bentonite mixtures and are often required for the design of the liner/barrier of the containments. A review of the literature showed that most of the past research work has focused on studying the influence of bentonite on the various geotechnical properties of sand–bentonite mixtures. In this study, the permeability, and strength characteristics of sand–bentonite mixture is investigated to support recommendation for a cost-effective liner material with locally available soil. Locally available Narmada sand of Jabalpur, Madhya Pradesh (India) was mixed with different proportions of sodium bentonite. A series of standard tests such as Modified Compaction test, Unconfined Compression Strength (UCS) test and Permeability test for strength and hydraulic conductivity characteristics, were conducted on different of sand- bentonite mixtures. The mixtures were formed by mixing local sand, with (0%, 5%, 10%, 15%, 20% and 25%) by dry of sodium bentonite. The investigations are presented to show the influence of bentonite clay on compaction, Atterberg limits, FSI, UCS, and permeability of Narmada sand by increasing the bentonite content 5% by weight each time. It was found that there is significant improvement in MDD and OMC of sand-bentonite mixture. This study focuses on the effect of bentonite content on strength and permeability, which are two important requirements of hydraulic liner material, of sand-bentonite mixtures.