composite geomembrane national standard certified waterproof and anti-seepage engineering limited-time low-price snap-up

Composite geomembrane: It is divided into one-layer and two-layer, with a width of 4-6m and a weight of 200-3000g/m². It is made of nonwoven geotextile, woven geotextile, or machine-woven geotextile combined with polyethylene. It can be called composite geomembrane by hot bonding or directly coating with polyethylene PE film. In addition, composite waterproof boards made of EVA materials can also be called composite geomembrane, and are widely used in tunnel projects of highways and railways. Some products of composite geomembrane and composite geotextile have different names, but they refer to the same product. Due to the emergence of geotextiles, there is no standardized name for the materials, which has caused confusion and irregularity in the definition of geomembranes. India developed jute geotextiles - in strict sense, all membrane-like materials used in civil engineering can be collectively called geomembranes. The so-called composite geomembrane is a geomembrane with a composite material or connected together to use for isolation and anti-seepage.

Composite geomembrane is simply a method of making plastic particles into plastic films by coating them, which is also known as waterproof sheets (depending on the thickness of the geomembrane). Because the composite geomembrane uses geotextile (woven fabric or plastic woven fabric) as the base fabric, it not only has the functions of soil separation, drainage, reinforcement, and protection, but also has the function of sealing (anti-seepage), which can be widely used in many fields such as water conservancy levees, road construction, airports, drainage, housing, environmental protection, etc. In the project, it mainly plays the roles of anti-seepage, protection, and reinforcement.

Performance

Composite geomembrane (composite anti-seepage membrane) has high physical and mechanical properties such as tensile strength, tear resistance, and bursting strength. The product has high strength, good stretching performance, large deformation modulus, resistance to acid and alkali, corrosion resistance, aging resistance, and good anti-seepage performance. It can meet the needs of civil engineering such as anti-seepage, isolation, reinforcement, and anti-crack reinforcement in water conservancy, municipal engineering, construction, traffic, subway, tunnel, and construction projects. It is often used for anti-seepage treatment of embankments and drainage channels, and for anti-pollution treatment of waste disposal sites.

Construction

Composite geomembrane is formed by heating one side or both sides of the film in a dryer using far-infrared heating, and then pressing the geotextile and geomembrane together through a guide roller to form a composite geomembrane. With the improvement of production technology, there is also a process of extrusion co-extrusion for making composite geomembranes. The forms include one geotextile and one geomembrane, two geotextiles and one geomembrane, and two geomembranes and one geotextile, etc.

Geotextile serves as a protective layer for geomembrane, protecting the anti-permeation layer from damage. To reduce UV exposure and enhance anti-aging properties, it is best to use the buried method for installation.

During construction, the first step is to level the base surface with sand or clay of smaller diameter, and then lay the geomembrane. The geomembrane should not be stretched too tightly, with the ends buried in the soil in a wavy pattern. Finally, a transition layer of about 10cm of fine sand or clay is laid on the geomembrane. Build a 20-30cm stone (or concrete precast blocks) as a protection layer against erosion. During construction, it should be avoided as much as possible for the stones to directly hit the geomembrane, it is best to lay the membrane while constructing the protection layer. The connection between the composite geomembrane and the surrounding structure should be anchored using expansion bolts and steel plate pressure strips, and the connection area should be coated with emulsified asphalt (thickness of 2mm) to adhere, to prevent leakage from occurring at this point.

Determination of the Compound Geomembrane's Resistance to Static Water Pressure

The principle of the composite geomembrane's resistance to static water pressure

After the pressure head of water on both sides of the composite geomembrane reaches a certain value, the composite geomembrane will break. Gradually increase the hydraulic pressure on both sides of the specimen, maintain for a certain time, and when the seepage rate rapidly increases, it indicates that the specimen is damaged, and the static water pressure resistance value of the specimen is obtained.

Maintain the above pressure on the composite geomembrane for at least 2 hours, and observe the change in water level in the seepage pipe. If the water level of the composite geomembrane is essentially stable (seepage flow is 0), then increase the pressure by 0.1-0.2MPa in steps, maintaining each step for 2 hours. Continue to increase the pressure until a rapid increase in seepage flow is observed, indicating that the sample has broken. The pressure level before this occurrence is the static water pressure resistance (MPa).

3. If only the soil membrane sample needs to be determined whether it meets a certain prescribed static water pressure value, it can be directly pressed to this pressure and maintained for 2 hours, and then the requirement is determined to be met.

Each sample of composite geomembrane shall be tested with at least three specimens, with the lowest value serving as the static water pressure resistance of the sample.

Construction Item Editing

(1) Use must be buried: the covering thickness should not be less than 30cm. Geomembrane is widely used in reservoir anti-seepage engineering.

(2) The repair of the anti-seepage system should include: a base layer, an anti-seepage layer, a transition layer, and a protection layer.

(3) The soil should be firm to avoid uneven subsidence and cracks. The turf and root systems within the anti-seepage range should be removed. A protective layer of small-grained sand or clay should be laid on the contact surface with the membrane.

(4) When laying geotextile membrane, do not pull it too tightly. It is better to form a wave-like pattern at the buried ends, especially when anchoring with rigid materials, leaving a certain amount of stretch.

(5) During construction, it should be avoided to drop stones or heavy objects directly onto the geomembrane. It is best to construct while laying the membrane and immediately cover the protective layer.