What Is a Geomembrane?
A geomembrane is an impermeable plastic sheet that can be used to contain liquid or gas. It can be used alone or in conjunction with a geotextile to form a composite liner system.
This research evaluated nine exhumed HDPE geomembranes and found that the quality control of resins and additives is crucial for the durability of this product, especially in civil construction applications where they will have long-term exposure to environmental conditions.
High Strength
A geomembrane is used to prevent seepage and isolation in various engineering projects. The material can be customized to match your specific needs and is highly durable. Its strength and high tensile properties make it an ideal choice for many different projects. It is also available in a variety of sizes, ranging from small fish ponds to large projects.
HDPE geomembranes are characterized by their high-strength, low-cost construction and long service life. They are durable and resistant to ultraviolet radiation. They can be used in a range of applications, including landfills and hazardous materials containment. They can withstand high temperatures and have excellent chemical resistance.
Compared to PVC, HDPE is also not prone to stress cracking. It is often used as a lining for landfills and other underground containment systems. It is also lightweight and easy to install, making it a cost-effective alternative to traditional liner materials.
A study of the durability of HDPE geomembrane liners found that they were able to withstand up to 30 years of exposure in landfills without significant loss of physical properties. However, the longevity of a liner depends on many factors, including its field conditions and mechanical stresses during geomembrane construction. It also depends on how it is maintained. For example, improper installation or inadequate maintenance can cause stress cracking and deterioration of the liner.
Low Cost
HDPE geomembranes are non-toxic and safe for use in ponds, lagoons and other containment applications. These liners are also inexpensive and easy to install. In addition, the long-lasting physical and mechanical properties make them highly cost-effective in the long run.
Using geomembranes to line canals and reservoirs minimizes seepage, ensuring that water volume can be delivered reliably for irrigation and other uses. Their impermeability also prevents contaminants from leaching into groundwater.
When constructed with good engineering and installation techniques, HDPE liners can reliably perform for 50 years or more. In addition to their durability, HDPE liners have superior chemical resistance and low-temperature flexibility.
Manufacturers can produce HDPE liner materials in sheets or in long, continuous rolls for ease of installation. Liner thickness can vary from 30 to 200 mils. Thicker liners provide greater puncture resistance and can be used in critical containment applications.
The manufacturing process begins with premium virgin HDPE polymer resins and additives like antioxidants, plasticizers and carbon black. The resulting formulation is then extruded, calendered or spread coated into various widths and thicknesses. Some manufacturers produce textured geomembranes with peaks and valleys that improve interface friction and stability. Ensure that the liner material you purchase meets key ASTM performance standards including tensile strength, elongation at break and puncture resistance, as well as environmental stress crack and UV radiation resistance.
High Chemical Resistance
In the construction of projects where the liner needs to be highly resistant to chemicals and harsh environments, HDPE geomembranes are the geomembrane liner best choice. They have excellent chemical resistance and can be welded together with hot wedge welding equipment to provide strong, durable lines that can last for years in harsh conditions.
For instance, in aquatic farming ponds where the water is treated to control pathogens and lower nutrient levels for the health of the fish and other aquatic life, HDPE liners can be safely used as a containment system. The strong and reliable properties of these liners ensure that the water stays inert in the pond, and the lining protects it from leaking or seepage, allowing aqua farmers to produce enough fish and other seafood to meet global demands without having to import it.
The chemical resistance of HDPE also makes it an excellent choice for landfill liners. It is highly resistant to the degradation of chlorinated hydrocarbons and resists oxidation by air, soil, and water. This durability extends the lifespan of a landfill, reducing costs and ensuring that waste will not be contaminated by toxic chemicals or airborne pollutants.
The thickness of a geomembrane can impact its longevity as well. Thicker liners are more resilient to damage during installation, long-term subgrade stresses and geotechnical forces, and weathering.
Good Weather Resistance
In addition to chemical resistance, HDPE is also known for its good weather resistance. While other liner materials can degrade or become brittle in sunlight, HDPE maintains its strength and flexibility. This makes it a better choice for exposed landfills, reservoir covers, and pond liners. It can also withstand higher temperatures, which is especially important in the case of mining projects where the liner will be used to contain tailings and heap leach mining wastes.
In the case of HDPE geomembrane, proper construction and maintenance are essential to maximizing its service life. This includes proper installation planning, surface preparation, deployment, seaming, and anchoring. It is also important to limit the number of days that the liner is exposed, as exposure can lead to premature wear and tear. To help prevent this, it is recommended that contractors only deploy as much of the liner as can be anchored and welded within one day.
It is also vital to have experienced engineers overseeing any liner project. Not only will they provide design and construction quality assurance, but they can also assist in integrating the liner system into broader stability solutions for mining infrastructure like tailings dams or heap leach pads. This can minimize the risk of damage to the liner and improve overall project performance. This, in turn, can help reduce the total cost of ownership and ensure that your project meets its original specifications.
