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A landfill is a secured engineered pit in the ground into which the wastes are dumped. Proper landfill liners need to be used to avoid any hydraulic connections between waste and surrounding environment. These liners can be created of different materials of which sand-bentonite mixtures are attracting greater attention. The sand bentonite mixture is a mixture of two different materials in terms of their particle size and chemical activity to produce a material with low hydraulic conductivity, low compressibility and sufficient strength. Low hydraulic conductivity of the mixture is due to the ability of bentonite particles to swell and fill the voids between the sand particles and whereas sand framework provides low compressibility. In this work, 80% sand and 20% bentonite were taken for the sand-bentonite mixture, on which various preliminary tests and secondary tests were carried out to study the properties of the mixture. The Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) were determined by Standard Proctor Test. Variation of unconfined compressive strength with curing period as well as with the water content on sand-bentonite mixture were obtained from the results of the tests performed in order to get the optimum curing period and water content. Hence, a suggestion can be made as to when the maximum Unconfined Compressive Strength (UCS) will occur at a particular curing period.

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In landfills, the compacted bentonite-sand (B:S) combination is widely employed as a liner. Since sand is a scarce and expensive material, other waste materials such as rock dust which possess similar properties are used instead of sand, or in other cases, both sand and rock dust are mixed in varying proportions along with bentonite. Urbanization and population explosion have triggered the continuous increase in industrial waste output, particularly waste tires, which posed several challenges to mankind. Incorporating wastes tire as raw resources have been suggested in various industries. Waste tires as stabilizers and investigation of geotechnical properties of the composite can help to minimize pollution while also providing economic and scientific benefits. Past research indicates short fibre has been shown to improve the ductility, toughness, and resistance to tensile cracking of clays. Fibre-shaped tire buffings or tire dust (T) from the retreading process can be used as a fibre reinforcing element in a liner. The objective of this study is to examine the effect of fibre-shaped tire dust (T) addition on the compaction characteristics of bentonite-sand (B:S),bentonite-rock dust (B:R), and bentonite-sand-rock dust(B:S:R) mixes. Locally available sand and rock dust, and commercially available bentonite have been used in this research. The gradation of the (T) used is equivalent to poorly graded sand. Here, all the mixes were prepared with different (T) contents (2 to 16%), and the standard compaction tests were performed. The results reveal that when the tire dust increases, the variation in the optimum moisture content and maximum dry density follow a consistent and predictable pattern. To put it another way, with the increase in the percentage of tire dust in the combination, the optimum moisture content increases while the maximum dry density decreases. Additionally, relationships were offered to predict the maximum dry density and the optimum moisture content with various tire dust content of the composite to be functional in the field