Bentonite waterproof blanket (geosynthetic clay liner) referred to as GCL is a new type of environmentally friendly composite waterproof and anti-seepage material, and it is also a waterproof material using the principle of bentonite expansion in water. It fills bentonite particles between woven geotextiles and non-woven geotextiles, and composites the upper non-woven fabric fibers through bentonite particles, special processes and equipment, and needle punching methods to connect the lower layer of woven fabrics. . GCL is an impermeable liner between GCL (in-situ thick compacted clay impermeable liner) and polymer material —- geomembrane.

Bentonite membrane has good adhesion, swelling, colloidal dispersion, thixotropy and cation exchange properties. Bentonite-based Si-Al-Si structure system is a single particle stacked by mica-like flake layers. During hydration, water molecules are adsorbed along the surface of Si-Al-Si structural units, increasing the distance between adjacent structural units. After hydration, the surface cations of bentonite are in a hydrated state, and after absorbing 2, 4 or 6 water molecules, it reaches saturation and becomes a gel, and its durability can reach 200 years. Bentonite usually begins to hydrate after being in contact with water for 24 hours, swells 4 to 5 times, and completes hydration after 48 hours, becoming a gel that is 10 to 15 times or even 30 times the original particle volume. In the confined space, the expansion of the bentonite in the waterproof blanket changes from disorder to order, and the continuous expansion of water absorption makes the waterproof blanket layer itself dense, its volume increases, and negative pressure is formed inside it to have waterproof function. Its permeability can be reduced to 10~9cm/s, and it is almost watertight.

We usually test the waterproof function by making a manmade lake in our workshop and please check the video below: