Bentonites as a basic material for technical base liners and site encapsulation cut-off walls

Bentonites and bentonite containing sealing materials are used for many years for sealing purposes in foundation, dike construction, hydraulic engineering and landfill construction, especially for encapsulation of old waste deposits. e of their exceptional physical, structural and chemical properties, bentonites are offering manifold possibilities to protect the environment against the negative effects of dumping grounds. the observance of legal regulations for waste dumping or for the encapsulation of contaminated areas is possible only by using bentonite containing sealing systems. fferent techniques of making horizontal technical base liners and vertical cut-off walls are illustrated as well as the essential properties of the bentonite with respect to the bentonite containing building materials. rizontal technical base liners the adsorption ability, the ion exchange capacity and the swelling behavior of bentonite is important. t-off walls bentonite controls the rheological behavior of the slurry and is responsible for the low permeability of the hardened bentonite-cement-wall. mposition and properties of mineral sealing mixtures are illustrated by examples of usage as well as the application in the building practice. s of recent developments for improving the material properties of bentonite containing mineral sealing mixtures, e.g. ready mixtures of bentonite/cement, are presented followed by a conclusive outlook to the further possible developments.