Effect of Bentonite and Cement on Permeability and Compressive Strength of the Compacted Soil Liner

벤토나이트와 시멘트가 매립장 차수층의 투수성과 압축강도에 미치는 영향(I)

This study discussed the optimal use of bentonite and cement for the compacted soil liner of landfill. Techniques employed in this optimization included permeability(by KSF 2322) and compressive strength(by KSF 2314). The optimal amount of these materials to the compacted soil liner was determined in accordance with a regulatory guideline of the government: that is, $k=1{\times}10^{-7}cm/sec$. The testing sods were CL(Clayey Soil) and SM(Sandy Soil), which were classified according to LSCS(Unifed Soil Classify System), The results showed that the optimal amounts of bentonite and cement to mix with the compacted CL soil liner were 5% of bentonite and 5% of cement : namely, $k=9.98{\times}10^{-8}cm/sec$ and ${\sigma}_{28}=1275kg/cm^2$. For the compacted SM soil liner. the optimal amount of bentonite was 15%, in conjunction with 5% of cement : namely, $k=9.86{\times}10^{-8}cm/sec$ and ${\sigma}_{28}=18.72kg/cm^2$. It was concluded that the compacted CL or SM soil liner, with containing the optimal amounts of bentonite and cement showed the acceptable permeability and the compressive strength, referring to a regulatory guideline of the government for construction of the landfill.

폐기물 매립지 차수층에 국내 투수계수 기준치($k=1{\times}10^{-7}cm/sec$)에 만족하는 벤토나이트와 시멘트의 적정첨가량을 알아보았다. 차수층의 모토는 토양 통일 분류법에 따라 CL 토양과 SM 토양을 사용하여 투수(KSF 2322)와 압축강도(KSF 2314)를 시험하였다. 실험결과, 국내 투수계수(k) 기준치에 만족하기 위해서는, CL 토양에는 벤토나이트 5%와 시멘트 5%를 첨가할 때, $k=9.98{\times}10^{-8}$이었고 ${\sigma}_{28}$은 $12.25kg/cm^2$이었다. SM 토양에서는 벤토나이트 15%와 시멘트 5%를 첨가하였을 때, k값은 $9.86{\times}10^{-7}cm/sec$이었으며 ${\sigma}_{28}$은 $18.72kg/cm^2$이었다. 따라서, 폐기물 매립지 차수층 건설에서, 적정량의 벤토나이트와 시멘트를 CL과 SM형 차수층 모토에 혼합할 때 국내 투수 기준치에 만족하였다.