Abstract

In modern landfills, the waste is contained by a liner system. The primary purpose of the liner system is to isolate the landfill contents from the environment and, therefore, to protect the soil and ground water from pollution originating in the landfill. Due to high swelling and adsorption capability, bentonite is commonly used material for liners. Sand is the basic material used with bentonite to improve its properties. Mixing sand with appropriate bentonite contents yields sand bentonite mixtures having low hydraulic conductivity that can be used as hydraulic containment liners. A series of laboratory experiments were conducted to evaluate the changes in soil properties such as consistency limits, compaction characteristics, hydraulic conductivity, strength characteristics and free swell index. In this study, compaction tests were conducted to determine the OMC and MDD of compacted M-Sand-bentonite mixtures. Hydraulic conductivity tests were conducted to assess the hydraulic conductivity of compacted M-Sand-bentonite mixtures. The M-sand bentonite mixture is tested to find out the exact proportion of the mixture which satisfies the landfill liner requirements.