ABSTRACT
We have seen from the previous chapters that the role of clay microstructure in smectite engineered barrier systems is fundamental for effective isolation of waste. A major attribute of the clay material is its low permeability since this impacts directly on its transmittance properties – especially in respect to the transport of pollutants in the soil. Other attributes for these types of expansive clays include: (a) their potential for volume expansion (swelling) upon water uptake, (b) the ability to seal internal cracks, joints and openings in tightly confined situations because of the constraints against swelling and volume expansion, (c) development of a more homogeneous macrostructure as a result of the tightly constrained swelling process and (d) a high capability for partitioning of inorganic and organic contaminants.
