LABORATORY TESTING OF BENTONITE CLAYS FOR LANDFILL DESIGN AND CONSTRUCTION

Abstract

Temeljni i pokrovni brtveni sustavi sastavni su elementi svakog odlagališta. Najčešće se izvode kao klasični sustavi od zbijene gline točno određenih svojstava (CCL – compacted clay liner) ili korištenjem nekog od alternativnih rješenja kao što su: bentonitni tepisi (GCL – geosynthetic clay liner), bentonitom poboljšana tla (BES – bentonite enhanced soils), te mješavine glina s polimerima. Prateći svjetske trendove, i u Hrvatskoj se već više godina primjenjuju bentonitni tepisi u odlagalištima otpada. Ovisno o mjestu ugradnje i namjeni, bentonitni tepisi moraju zadovoljiti različite kriterije. Sukladnost s propisanim kriterijima potvrđuje se različitim laboratorijskim postupcima. U ovom radu prikazani su rezultati ispitivanja posmične čvrstoće i kemijske kompatibilnosti bentonitnih tepiha, te probna ispitivanja hidrauličke propusnosti na uzorcima kaolinske gline.Top and bottom liners are one of the key construction elements in every landfill. They are usually made as compacted clay liners (CCLs) composed of several layers of compacted clay with strictly defined properties or by the use of alternative materials such as: GCL – geosynthetic clay liner, BES – bentonite enhanced soils or bentonite/polymer mixtures. Following the state of the art experiences in the world, GCLs are used in Croatian landfills for several years, as well. Depending upon the location and the obeying function, GCLs have to fulfill certain conditions. A legislated compatibility criterion has to be proven by various laboratory tests. In the paper are presented the results of direct shear and chemical compatibility tests of GCLs as well as the results of permeability measurement of kaolin clay