At Imerys Civil Engineering, we have extensive experience with both one-phase and two-phase slurry wall construction and can adjust the quality of our bentonite to meet the precise needs of our customers and the specifics of each project. We offer slurry wall bentonites for two-phase construction and cement-stable bentonites for preparing self-hardening slurry on-site that provide guaranteed results in the one-phase method.
Diaphragm/Slurry wall is a sealing method in hydraulic and earth works for creating impermeable to water underground barriers wherever needed. This sealing method is especially popular in retention dams, levees and dykes for seepage control, in landfill projects to divert uncontaminated ground water flow from contaminated subsoil, as a ground water barrier and for trench/building-pit sealing and consolidation applications. Slurry walls can be constructed using a one-phase or two-phase method.
In a two-phase method, a trench is excavated initially using a backhoe or a clam-shell and under the support of a prehydrated bentonite slurry. The bentonite slurry is used primarily for trench stabilization during excavation. Following this, the bentonite suspension is pumped out and replaced by the actual sealing material.
In the one-phase method, the supporting fluid consists of bentonite, cement and other cementitious materials and water. Initially, the slurry is used for supporting the trench during excavation as in the two-phase method; however, this slurry gradually hardens as a result of the cement in the mixture. In that way there is no need for pumping out the slurry. This is often called self-hardening slurry.