Slurry walls are constructed using a cement-bentonite slurry to produce a below ground low permeability barrier.

Common uses

Create barriers to groundwater flow
Encapsulate contaminated groundwater and leachates
Prevent the lateral migration of gas when combined with an HDPE liner
Typically installed for dam core cutoff, flood water control and landfill sites

Process

A slurry cut-off wall or slurry trench wall is typically excavated using a backhoe (or grab) while simultaneously pumping a hydrated cement bentonite mix into the trench to depths in excess of 25m. Once cured, the slurry cut-off wall provides a permanent low permeability barrier to groundwater and leachates.

Where gas migration is the issue a high-density polyethylene membrane is placed in the wall in panels connected with an interlock system.  

Advantages

Quick installation
Low cost solution for low permeability barriers
Permeability 1x10-9m/sec
Resistant to range of heavy metals and organic contaminants including volatile organic compounds (VOCs), hydrocarbons, diesel, solvents and tars

Quality assurance

Keller has decades of experience installing slurry walls across the globe.

A specially developed mix combined with strict quality control ensures consistency and a product installed and designed to withstand the test of time.

Samples from the top and bottom of the trench are taken daily and a series of testing can be done including slump, specific gravity, bleed, shear strength and pH.