slurry walls

Slurry (or cut off) walls are non structural walls excavated in the same manner as diaphragm walls however usually a single phase self setting bentonite cement material is used to form a low permeability “plastic” wall capable of restricting flow of liquids such as groundwater or leachate. Soil bentonite walls can also be used, wherein the excavated material is mixed with a bentonite mud and replaced into the trench in a two phase operation. 

Where migration of gases is to be controlled a thin HDPE Membrane can be introduced into the slurry trench prior to set to provide a very low permeability barrier to gases and liquids.

Depending on depth requirements the slurry wall can be excavated using a long reach excavator, or by using grab and cutter methods similar to those for diaphragm walls.