What is Geomembrane? | What are the types of the Geomembranes?

What is Geomembrane?

geomembrane is a very low permeability synthetic membrane barrier, sheet, or liner used within soils so as to control fluid (liquid or gas) migration in a human-made project, structure, or system.

Geomembrane

Geomembranes are made from relatively thin continuous polymeric sheets, but they can also be made from the impregnation of geotextiles with asphalt, elastomer, or polymer sprays or as multilayered bitumen geocomposites. Continuous polymer sheet geomembranes are, by far, the most common.

Geomembranes that are used in waste landfills may be compromised by low frictional behavior. This is a serious cause of instability of waste landfill structures.

Geotextile–geomembrane composites are made to improve the protection function of geomembranes as water barriers in waste landfill systems and avoid frictional instability. It is known that HDPE geomembranes and polypropylene geotextiles can be thermally bonded to make composites to improve the frictional property of the composite. 

Types of Geomembranes

1) HDPE Geomembrane

HDPE (High-Density Polyethylene) is the most widely used geomembrane and is the preferred choice for lining projects due to its durability, strong UV resistance, and relatively inexpensive material cost.

HDPE geomembranes are often selected for use in exposed applications such as landfills, reservoir covers, ponds, and canal liners. This is due to the low initial material cost and its high resistance to chemicals. It is available in higher thicknesses which other geomembrane types do not offer.

HDPE geomembrane is also very strong relative to its weight and can resist higher temperatures.

One of the best characteristics of this geomembrane is its chemical and UV resistance, making it suitable for large-area applications where high-quality installation is required. Additionally, HDPE is food safe, allowing it to be used in the storage of potable water.

2) TRP Geomembrane

Reinforced Polyethylene (TRP) geomembranes are almost the same as the RPP but use polyethylene fabric instead of polyester. This is an ideal option for lining your temporary retaining ponds.

TRP geomembranes are also a durable solution for soil remediation. Its physical properties include chemical resistance, low-temperature range, and ultraviolet stability. This type of geomembrane is used for canals, industrial tarps, landfills, agricultural and municipal applications.

3) PVC Geomembrane

Polyvinyl Chloride (PVC) geomembranes is a thermoplastic waterproofing material made with vinyl, plasticizers, and stabilizers. The polyvinyl chloride resin used for PVC geomembranes is made by cracking ethylene dichloride into a vinyl chloride monomer. It is then polymerized to make PVC resin.

It is tear, puncture, and abrasion-resistant, meaning the material is perfect for preventing contaminants from entering water sources and maintaining potable drinking water.

PVC geomembranes are highly flexible and are best suited for landfills and canals, tank linings, soil remediation, and wastewater lagoon liners.

4) EPDM Geomembrane

Ethylene Propylene Diene Monomer (EPDM) geomembrane is a flexible and durable material that can resist punctures and extreme weather conditions. It has a rubber-like texture and is UV-stable with great strength.

EPDM geomembranes are typically used as surface barriers for dams and other irrigation sites. It’s also easy to install, which is why backyard landscapers use this type of geomembrane. It’s suitable for agricultural applications such as irrigation ponds as well as liners and covers.

5) RPP Geomembrane

RPP (Reinforced Polypropylene) geomembranes are polyester-reinforced liners made from a UV-stabilized polypropylene copolymer that gives the material stability, chemical resistance, and flexibility.

Its strength and durability can be traced to the support it gets with nylon scrim. RPP geomembranes are ideal for long-term water containment and industrial waste applications.

RPP geomembranes are perfect for applications where folds appear due to uneven and inconsistent weather conditions. This type of geomembrane is typically used in municipal applications, aqua and horticulture, evaporation pond liners, and mine tailings.

6) LLDPE Geomembrane

Linear Low-Density Polyethylene (LLDPE) geomembranes provide more flexibility than HDPE, making it more appropriate for installers who require an impermeable geomembrane. It is made with virgin polyethylene resins, making it resistant to low temperature and ultraviolet exposure.

LLDPE geomembranes are also meant for long-term use and will remain strong and durable for years. Its best use relates to industrial applications, such as liquid storage tanks, environmental and animal waste containment.

What is the difference between geomembrane and geotextile?

  1. The geotextile is made of non-woven fabric, while the geomembrane is made of high-density polyethylene, which is used to prevent seepage. Geomembrane and geotextile are both used geotechnical materials. 
  2. Geotextile is a permeable geosynthetic material made of synthetic fibers through needle punching or weaving. It is used in roads, railways, water conservancy, large buildings, power plant ash dam construction, non-ferrous metal tailings treatment, environmental protection engineering, soil and water conservation, Geomembrane is a plastic film, and geotextile is a fiber cloth geotextile used in roads, railways, water conservancy, large buildings, power plant ash dam construction, non-ferrous metal tailings treatment, environmental protection engineering, soil and water conservation, etc.
  3. Geomembrane is impermeable, and geotextile is permeable.

Read More: Different types of Geotextile

Advantages of Geomembrane

  1. The geomembrane improves the work environment
  2. Increase the turn-around time between corps
  3. Provide positive water containment
  4. Prevent the loss of dissolved oxygen
  5. Help sustain water quality
  6. Manage waste removal
  7. Establish erosion control
  8. Lower disease risk
  9. Reduce maintenance cost

Applications of Geomembrane

Geomembranes are used in the following environmental, geotechnical, hydraulic, transportation, and private development applications:

  • As liners for reserve water (e.g., safe shutdown of nuclear facilities)
  • To contain seepage losses in existing above-ground tanks
  • As liners for waste liquids (e.g., sewage sludge)
  • Liners for radioactive or hazardous waste liquid
  • As liners for secondary containment of underground storage tanks
  • As containment structures for temporary surcharges
  • As liners for brine solutions
  • As liners for the agriculture industry, such as fish/shrimp pond
  • As liners for the agriculture industry
  • As liners for solar ponds
  • As liners for golf course water holes and sand bunkers
  • As liners for water conveyance canals
  • As liners for all types of decorative and architectural ponds
  • As liners for various waste conveyance canals
  • As liners for heap leach pads
  • As covers (caps) for solid-waste landfills
  • As liners for primary, secondary, and/or tertiary solid-waste landfills and waste piles
  • As covers for aerobic and anaerobic manure digesters in the agriculture industry
  • As covers for power plant coal ash
  • As cutoffs within zoned earth dams for seepage control
  • As liners for vertical walls: single or double with leak detection
  • As linings for emergency spillways
  • As waterproof facing of earth and rockfill dams
  • As waterproofing liners within tunnels and pipelines
  • As waterproof facing for roller compacted concrete dams
  • As waterproof facing for masonry and concrete dams
  • As floating reservoirs for seepage control
  • As floating reservoir covers for preventing pollution
  • Within cofferdams for seepage control
  • To contain and transport liquids in trucks
  • As a barrier to odors from landfills
  • To contain and transport potable water and other liquids in the ocean
  • As a barrier to vapors (radon, hydrocarbons, etc.) beneath buildings
  • To control frost-susceptible soils
  • To control expansive soils
  • To shield sinkhole-susceptible areas from flowing water
  • To form barrier tubes as dams
  • To prevent infiltration of water in sensitive areas
  • To face structural supports as temporary cofferdams
  • Beneath highways to prevent pollution from deicing salts
  • Beneath and adjacent to highways to capture hazardous liquid spills
  • To conduct water flow into preferred paths
  • Beneath asphalt overlays as a waterproofing layer
  • As liners for potable water
  • As flexible forms where the loss of material cannot be allowed

Geomembrane Durability 

Several factors affect the degradation of polymers within the geomembranes. Factors like UV exposure, chemical impact, biological contaminants (animal, fungi), and thermal expansion impact the life span of the geomembranes.

Technical expertise is necessary when selecting the right type and thickness for the project. This is generally based on the depth of the containment and the geotechnical conditions of the site.

Please see the corresponding depth and thickness chart for a general overview. This is for guidance only:

Liquid depth ≤ 1m 0.5mm thickness 
Liquid depth 2m to 4m 1.5mm thickness
Liquid depth 1m to 2m 1.0mm thickness 
Liquid depth ≥ 4m2.0mm thickness

FAQ Section

What is geomembrane used for?

Geomembranes are giant impermeable membranes made of (un)reinforced polymeric materials and used to stabilize the earth and secure landfills, ensuring containment of hazardous or municipal wastes and their leachates.

What is geomembrane lining?

A geomembrane is a very low permeability synthetic membrane liner or barrier commonly used to control fluid (or gas) migration in a human-made project, structure, or system.

Is geomembrane waterproof?

Geomembranes are waterproof sheets that are used as hydraulic barriers. They are available in different widths and packed in rolls joined by different techniques such as Thermofusion, welding, adhesive, vulcanization methods, etc.

What is geogrid used for?

Geogrid is a flexible mesh that is used to create a reinforced coherent mass behind the retaining wall by stabilizing the soil. The stability of the soil depends greatly on the friction angle it contains. The friction angle is often referred to as the shear strength of the soil.

What is geosynthetics engineering?

Geosynthetics are synthetic products used to stabilize terrain. They are generally polymeric products used to solve civil engineering problems. This includes eight main product categories: geotextiles, geogrids, geonets, geomembranes, geosynthetic clay liners, geofoam, geocells, and geocomposites.

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