Slurry Walls are formed by using a specially formulated mix of cementitious and bentonite based materials together with proprietary additives to provide a plastic structure that offers extremely low permeability with a degree of flexibility.
The wall can form a barrier to the passage of leachates and ground water flows, to prevent the contamination of adjacent ground and water courses. With appropriate additional design the wall can act as a barrier to the migration of landfill gas.
Excavation of the wall is normally carried out using a long reach excavator. For deeper walls, grabbing techniques similar to those used for constructing diaphragm walls are used.
A bentonite/cement slurry is prepared at a central mixing and batching station using high shear colloidal mixing techniques. Precise batching and monitoring of the mix constituents is essential for uniformity of the final product.
As excavation proceeds the slurry is pumped from the mixing station to the excavation.
The bentonite/cement slurry mix maintains the sides of the excavation to provide temporary stability until a set occurs and the mix hardens in-situ to form the permanent wall.