5. The materials

5.1 The main grout families

Most containment techniques use a mixture comprising at least one hydraulic binder.

Grout, the basic product, is composed of clays, more specifically bentonite, and a hydraulic binder, generally cement.

Bentonite is a natural clay from the smectite family, composed mainly of montmorillonite. Its primary role is to prevent sedimentation of grout components and thus keep cement grains in suspension.

Cements are hydraulic binders. In contact with water, the hydration of these components causes the cement to set and harden. Standard NF 15-301 is a guide to the use of hydraulic binders.

Additives may be added to the composition of the product, depending on the intended...