UTILIZATION OF BENTONITE-SILT MIXTURES AS SEEPAGE BARRIERS IN LINER SYSTEMS OF ENGINEERED LANDFILLS

The permeability and compaction characteristics of several bentonite-silt mixtures were determined and effects of bentonite content on the above stated characteristics were investigated. Standard proctor test were conducted on both silts and silts stabilized with 3, 6, 9, 12 and 15% of bentonite clay by weight. For both type of silts values of MDD increases and OMC decreases with increase in percentage of bentonite as an additive. To ensure consistent performance of these clay liners, they were compacted to maximum dry density (MDD) by adding optimum moisture content (OMC). Falling head permeability test were conducted on compacted plastic and non-plastic silt samples stabilized with 3, 6, 9, 12 and 15% % of bentonite clay by weight. The permeability values for all silt-bentonite mixtures were measured. A Significant decrease in values of permeability was observed for both types of silt-bentonite mixtures with increase in percentage of bentonite clay as an additive.