Volume 34, N. 1, January-April 2011 | PDF(0 downloads)
Geosynthetic clay liners (GCL) have been increasingly used in barrier systems of waste disposal areas and in hydraulic
works. However, sometimes they are discarded as possible barrier solutions in these works because of their greater costs in
comparison with other solutions (geomembranes or compacted clay liners). This paper presents a laboratory study to investigate
the technical feasibility of mixing alternative materials to bentonite for the production of alternative low cost GCLs. The
alternative materials used were sand, clay and tire grains. Direct shear, consolidation, and expansibility tests were carried out on
bentonite mixtures with varying percentages in mass of the alternative material. Ramp tests and expansibility tests were also
performed on alternative GCLs manufactured with these types of mixtures. The results obtained showed that the presence of the
alternative materials in the bentonite increased the shear strength and the permittivity of the mixture and reduced its expansibility.
The tests on the bentonite-tire grains mixtures suggest that alternative GCLs manufactured with this type of mixture may be used
in less critical barrier systems (particularly under high stress levels) and as bedding/protective layers underneath geomembranes,
also providing a better use for wasted tires in environmental terms.