ABSTRACT
The 'combination liner' is a special design of a composite liner in which a synthetic membrane is placed directly on top of a mineral liner. Because of its advantages, the combination liner has become the standard lining system in Germany. The suction is presented in pF, which is the logarithm of the negative pressure head in centimetres of water. The absolutely-sealed upper ends of the test facility were heated to 30 C, representing the temperature of the leachate in landfills. The tests described above do not respect the overburden pressure due to the waste. The results as described above also show that the calculation may include gravity and other effects as the dependency of the diffusion coefficients on moisture content. The following options may be respected during the design of the mineral liner: The desiccation of mineral layers in the base lining system of landfills may influence the permeability of the liner due to cracking.
