Mixtures of lateritic soil and bentonite as an alternative barrier for sanitary landfills in Brazil
DOI:
https://doi.org/10.24849/j.geot.2015.134.03Keywords:
Sanitary landfill, Later, Bentonite, Hydraulic conductivity, Shear strengthAbstract
In 2014 most Brazilian cities had not yet managed to comply with the National Policy for Solid Waste (PNRS), which implies that all urban waste not recycled must be disposed of on proper sanitary landfills. In this context, the use of a barrier composed of lateritic soil seems to be a reasonable alternative to substitute or complement geosynthetic barriers, considering the abundance of this type of soil in the tropics. However, some lateritic soils may not exhibit the low hydraulic conductivity (k) levels demanded by landfill design and bentonite addition could reduce the k of these soils. This paper reports the results of laboratory research on mixtures of bentonite and a lateritic soil from the region of Ouro Preto MG, Brazil. The study aimed to determine the reduction of hydraulic conductivity of lateritic soil due to the addition of bentonite, and to evaluate the possible decrease in shear strength for application in landfill base sealing systems. The experimental work involved characterization, hydraulic conductivity and shear strength determination. As a general conclusion, the research indicated the suitability of these mixtures as an alternative for liner construction, once the interaction of the bentonite and the lateritic soil is correctly addressed.
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