Composition and production of geomembranes

This article on the composition and production of geomembranes aims to familiarize readers with this relatively new material. Geomembranes are flexible waterproof materials used in civil engineering works, such as:

• the tanks;

• the dams;

• the channels;

• waste storage facilities;

• mine waste storage facilities and many other types of structures.

This article describes geomembranes, explaining what they are made of and how they are manufactured. The information provided in this article should enable engineers who decide to use a geomembrane to understand and anticipate the practical implications of their decision.

First, this article presents the main component of a geomembrane: the waterproof compound. The base material of the waterproof compound, which is polymer or bitumen, gives the geomembrane its waterproof properties. However, this base material is never used alone. In addition to the base material, the waterproof compound includes additives that have various functions, such as:

• reduce the cost;

• facilitate production;

• improve sustainability, etc.

Since some geomembranes are reinforced, the article describes the various textile products used to reinforce geomembranes. The reasons why some geomembranes are reinforced are analyzed, with a discussion of the advantages and disadvantages of this reinforcement.

The main methods of geomembrane production are described:

• extrusion;

• calendering;

• impregnation;

• coating;

• co-extrusion;

• co-lamination, etc.

Since the surface condition of geomembranes is important, particularly to ensure their stability on slopes, the production of geomembranes with a rough surface is discussed.

The methods for joining geomembranes are described in detail. These methods depend on the type of geomembrane. Bituminous and thermoplastic polymer geomembranes are heat-sensitive and can therefore be thermally welded. Elastomeric polymer geomembranes are not sensitive to temperature and therefore cannot be welded. They must be assembled using special adhesive tapes.

Quality control of geomembranes is essential. It must be carried out at the factory during the production of geomembranes, in the...