What is Bentonite waterproof blanket (bentonite anti-seepage blanket)?

Bentonite waterproof blanket (bentonite anti-seepage blanket) is a geosynthetic material specially used for anti-seepage in artificial lake waterscape, landfill, underground garage, roof garden, pool, oil depot and chemical storage yard. The following is a detailed introduction to bentonite waterproof blanket:

1. Structure and principle
The bentonite waterproof blanket is made of highly expansive sodium-based bentonite filled between special composite geotextile and non-woven fabric, and is made by needle punching. This process enables the bentonite anti-seepage mat to form many small fiber spaces, so that the bentonite particles cannot flow in one direction. When encountering water, the bentonite particles form a uniform and high-density gel-like waterproof layer in the mat, thereby effectively preventing water leakage.

2. Classification
The bentonite waterproof blanket can be divided into the following types according to the production process:

Needle punch sodium-based bentonite waterproof blanket: bentonite waterproof blanket made directly by needle punching.
Needle-punched sodium bentonite waterproof blanket: A layer of high-density polyethylene geomembrane is compounded on the outer surface of the non-woven geotextile of the needle-punched sodium bentonite waterproof blanket.
Adhesive sodium bentonite waterproof blanket: A sodium bentonite waterproof blanket produced by bonding bentonite particles to high-density polyethylene boards with adhesives and compressing them.

3. Features and advantages
Bentonite waterproof blanket has many characteristics and advantages, making it the preferred waterproof material in many engineering fields:

Compactness: Sodium bentonite forms a high-density diaphragm under water pressure and has strong self-retention ability. When its thickness is about 3mm, its water permeability is less than α×10-11m/sec, which is equivalent to the compactness of 30cm thick clay 100 times thick.
Long-lasting waterproof performance: Sodium bentonite is a natural inorganic material. Even if it is exposed to long-term changes or the surrounding environment changes, it will not age or corrode, so the waterproof performance is long-lasting.
Simple and quick construction: The construction of bentonite waterproof blanket is relatively simple, without heating and gluing. Only bentonite powder, nails, washers, etc. are needed for connection and fixing. No special inspection is required after the construction is completed, and waterproof defects are easy to repair.
Not affected by temperature: bentonite waterproof blanket will not become brittle in cold climates and can be constructed at negative temperatures of -20℃.
Integrated performance: When sodium-based bentonite reacts with water, its expansion capacity is 13 to 16 times that of water. Even if the concrete structure vibrates and settles, the bentonite waterproof blanket can repair cracks on the concrete surface within a range of 2mm.
Green and environmentally friendly: bentonite is a natural inorganic material that is harmless and non-toxic to the human body, has no special impact on the environment, and has good environmental performance.

4. Scope of application
Bentonite waterproof blanket is mainly used in waste landfills, underground reservoirs, underground infrastructure construction and other projects in environmental engineering to solve sealing, isolation, and anti-leakage problems. It is also suitable for underground waterproofing and anti-seepage projects in municipal, highway, railway, water conservancy, environmental protection, and industrial and civil buildings. Specifically, bentonite waterproof blanket can be used for:

The main lining and secondary lining of the landfill.
Isolation layer between artificial fill, rock pile or material field and foundation.
Isolation between different frozen soil layers.
Filter layer of water wells, pressure relief wells or inclined pressure pipes in water conservancy projects.
Filter layer of the initial upstream dam surface of ash storage dam or tailings dam.
Increase the stability of gravel slope and reinforced soil, etc.

5. Construction precautions
The construction of bentonite waterproof blanket should be carried out under the condition that the outdoor air temperature is not lower than 0℃ or higher than 40℃.
The bentonite waterproof blanket cannot be unfolded in windy weather to prevent it from being blown away by the wind.
The laying method of bentonite waterproof blanket must ensure that it is in direct contact with the foundation below and eliminate wrinkles. Any wrinkles, folds or arches may cause the same situation to other geotechnical materials in the soil layer.
After the bentonite waterproof blanket is laid, the geomembrane should be laid in time to avoid erosion by wind and rain. If the geomembrane cannot be laid in time, it should be covered with colored strips or film.
After the construction is completed, there should be no mud, dirt, debris or other foreign matter on the bentonite pad that may damage the anti-seepage layer.

In summary, bentonite waterproof blanket plays an important role in waterproof and anti-seepage projects with its unique structure, excellent performance and wide range of applications.

Request Free Samples/Quote