Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

The objective of this study is to evaluate the utilization of soil-bentonite mixture from Chongju area as a disposal liner. The main materials were the clay from Chongju landfill site and the granitic soil from Chongju area. Bentonites from Jeil mine and IMK company were also selected as an additive. The mineralogical, geochemical, physical and dynamic properties of the selected materials were investigated, and the test results showed that the engineering properties of Chongju landfill clay were 29.4% of the liquid limit, 3.5% of the plasticity index and 1.63×10 -7(cm/sec) of the hydraulic conductivity. The Chongju granitic soil was the non-plastic and the hydraulic conductivity was 1.12×10 -3(cm/sec). The Chongju landfill clay and the Chongju granitic soil were not suitable for the landfill liner. As the mixed ratio of bentonite in soil-bentonite mixture increased, the maximum dry unit weight increased at 5% mixture and then decreased constantly. On the other hand, the optimum moisture content increased gradually. The unconfined compressive strength of soil-bentonite mixture increased rapidly with an addition of 5% bentonite and at 7 day curing time. The hydraulic conductivity of soil-bentonite mixture decreased as the mixed ratio of bentonite increased. Upon the results of hydraulic conductivity, the landfill liner may be applicable when the mixed ratio of bentonite is more than 15% for Chongju granitic soil and 5 to 10% for Chongju landfill clay.