Composite Geomembrane

What‘s Composite Geomembrane?

Lianyi®Composite geomembrane is a kind of geosynthetic material made by combining geomembrane (anti-seepage layer) and geotextile (protective layer) through methods such as hot pressing or adhesive bonding. It combines the excellent impermeability of geomembrane with the good mechanical properties and reverse filtration and drainage functions of geotextile.

Core Structure and Function

Composite geomembranes usually adopt a “sandwich” structure, generally being “one membrane and two fabrics” (one layer of geomembrane is compounded with one layer of geotextile on each side) or “one membrane and one fabric” (one layer of geomembrane is compounded with geotextile on only one side).

1.Core layer: Geomembrane

*Materials: Mainly high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyvinyl chloride (PVC) and other polymers are used.

*Function: Provide core anti-seepage and isolation functions. Its permeability coefficient is extremely low (usually < 10⁻¹¹ cm/s), which can effectively prevent the leakage of water or contaminants.

2.Protective layer: Geotextile

*Material: Usually short-fiber or long-fiber non-woven fabric made of polyester (PET) or polypropylene (PP).

*Function

Protection: Prevent the geomembrane from being punctured by sharp objects such as sand, gravel, backfill soil, etc. on the upper and lower layers.

Drainage and exhaust: The non-woven fabric structure can guide and discharge pore water and gas parallel to the membrane surface, eliminate water vapor pressure, and prevent the membrane from being punctured.

Increase friction: Enhance the friction coefficient of the material surface, improve the stability of the contact surface with the soil, and prevent sliding during slope laying.

Features Of Composite Geomembrane

*It has excellent anti-seepage performance: this is its most core feature.

*Strong puncture and tear resistance: Geotextiles significantly enhance the mechanical strength of the overall material, making it more durable.

*High friction coefficient: It combines more firmly with the soil and has better slope stability.

*Convenient construction: The composite material can complete the two processes of anti-seepage and protection in one laying, which improves the construction efficiency.

Application Of Composite Geomembrane

Composite geomembrane is an indispensable material in modern anti-seepage projects and is widely used in:

*Water conservancy projects: Anti-seepage linings for reservoirs, DAMS, rivers and canals; Anti-seepage for water gates and pumping stations.

*Environmental protection project

*Landfill: As the base cushion layer and top cover layer, it prevents the leachate from garbage from polluting the underground soil and water bodies.

*Anti-seepage for regulating tanks, sedimentation tanks and evaporation ponds in sewage treatment plants.

*Tailings ponds and red mud storage yards: Prevent the leakage of harmful components from industrial waste residues.

*Traffic engineering: Anti-seepage isolation of highway and railway subgrades; Waterproofing for tunnel engineering.

*Construction engineering: Waterproofing and moisture-proofing for basements and rooftop gardens.

*Aquaculture: Anti-seepage linings for aquaculture ponds and fish ponds.

Precautions for Purchase and Construction

Index selection: Reasonable specifications should be chosen based on the engineering design requirements, including:

*Mass per unit area (e.g., 600g/m², 800g/m²)

*Geomembrane thickness (e.g., 0.5mm, 1.0mm)

*Breaking strength, tear strength, CBR puncture strength

*Permeability coefficient

*Welding process: After laying, the pieces need to be formed as a whole through hot wedge welding or hot air welding, and the weld seams should undergo strict non-destructive (air pressure testing) and destructive testing (sampling for tensile testing) to ensure the integrity of the anti-seepage system.

*Anchoring: Reliable anchoring treatment is required at the structural edge.

In summary,composite geomembrane is a high-performance engineering material that achieves a “1+1 > 2” effect through material composite technology. It integrates anti-seepage.