In projects involving mining, sewage treatment and canal construction, geomembranes are used in conjunction with other geosynthetic products to control fluid movement and provide containment.

What is the meaning of geomembranes?

The term “geomembrane” refers to a synthetic material coating with very low permeability.

A geomembrane is commonly used to confine hazardous substances that, if not properly controlled, can pollute the ground or nearby buildings.

When it comes to geomembranes, the chemical resistance of the liner is frequently emphasized.

Larger size liners with a certain type of liner are referred to as “geomembrane liners” in engineering.

Traditional goods like concrete, asphalt and compacted clay have been shown to be significantly less effective than geomembranes.

They preserve our environment and our water resources by exhibiting a wide range of physical, mechanical and chemical resistance qualities.

Because geosynthetic containment systems are less vulnerable to ground movement, they are now widely regarded as the most cost-effective and safest way of installation in the vast majority of cases.

The geomembrane can be textured or smooth.

Because the smooth (flat) geomembrane bonds poorly to soil surfaces, the textured geomembrane is recommended for use on slopes.

The structure of the textured geomembrane allows it to perform not only waterproofing but also drainage duties.

Application of geomembrane:

1-It is utilized by industrial businesses to keep harmful liquids and filtrates from leaking.

2-Geomembrane is utilized in municipal services to create sewage treatment plants and potable water

3-The geomembrane is used in agriculture to isolate diseased soil.

4-Pond and reservoir waterproofing is accomplished using a geomembrane (a pond liner). Ponds must be waterproofed to prevent the creation of silt, water leaks and other problems.

Why it’s important?

All of the advantages of geomembrane include increased turn-around time between corps, improved work environment, ensure effective water containment, contribution to the preservation of water quality, establish erosion control measures, Lower illness risk, lower maintenance costs control garbage removal and stopping the loss of dissolved oxygen.

Types of geomembranes

High-density polyethylene (HDPE)

Because of its longevity, good UV resistance, and low material cost, HDPE (High-Density Polyethylene) is the most often used geomembrane and the favored choice for lining projects.

HDPE geomembranes are frequently chosen for usage in exposed applications such as landfill covers, reservoir covers, and pond and canal liners.

This is owing to the low initial material cost and good chemical resistance.

It is available in greater thicknesses than other geomembrane varieties. HDPE geomembrane is also quite strong for its weight and can withstand greater temperatures.

One of the main features of this geomembrane is its chemical and UV resistance, which makes it suited for large-area applications requiring high-quality installation.

(LLDPE) geomembrane

Linear Low-Density Polyethylene (LLDPE) geomembranes are more flexible than HDPE, making them a better choice for installers who need an impermeable geomembrane.

It is made of virgin polyethylene resins, which make it resistant to low temperatures and UV light.

LLDPE geomembranes are also designed for long-term use, remaining strong and durable over many years.

Its finest applications are in industrial settings, such as liquid storage tanks and environmental and animal waste containment.

PVC Geomembrane

PVC geomembranes are thermoplastic waterproofing materials produced from vinyl, plasticizers and stabilizers.

Polyvinyl chloride resin, which is utilized in PVC geomembranes, is created by splitting ethylene dichloride into a vinyl chloride monomer.

The PVC resin is then polymerized.

It is tearing, puncture and abrasion resistant, making it ideal for keeping contaminants out of water sources and ensuring potable drinking water.

PVC geomembranes are extremely flexible, making them ideal for landfills and canals, tank linings, soil remediation, and wastewater lagoon liners.

EPDM Geomembrane

EPDM geomembrane is a flexible and long-lasting material that can withstand punctures and adverse weather conditions.

It has a rubber-like texture and is UV-stable and extremely strong.

Typically, EPDM geomembranes are employed as surface barriers for dams and other irrigation facilities.

This type of geomembrane is relatively simple to install, which is why it is used by backyard landscapers.

It is appropriate for agricultural applications such as irrigation ponds, liners, and covers.

RPP Geomembrane

RPP geomembranes are polyester-reinforced liners used for long-term water containment and industrial waste applications.

It is comprised of a UV-stabilized polypropylene copolymer, which provides flexibility, stability and chemical resistance.

RPP geomembranes are ideal for applications involving folds caused by unequal and unpredictable weather conditions.

It is reinforced with nylon scrim to assure its strength and durability.

This form of geomembrane is commonly utilized in municipal applications, aquaculture, evaporation pond liners and mine tailings.

TRP Geomembrane

Reinforced Polyethylene (TRP) geomembranes are similar to RPP geomembranes but use polyethylene fabric rather than polyester.

This is an excellent choice for lining temporary retaining ponds.

TRP geomembranes are also a long-lasting soil remediation option.

Chemical resistance, a low-temperature range, and ultraviolet stability are among their physical features.

Geomembranes of this sort are utilized in canals, industrial tarps, landfills and agricultural and municipal applications.

Geomembranes Lining Systems Installation

Installing geomembrane lining systems is a difficult task that is best left to experienced engineers and personnel.

To guarantee that any geomembrane lining system is effectively installed, several specialized welding methods, site preparation and installation experience are necessary.

The following is a generalized yet representative geomembrane installation procedure:

Quality Assurance Inspection: To assure quality geomembrane installation, the following things are examined:

1-Before the lining was installed, the surface conditions had to meet all standards.

2-The geomembrane rolls were successfully deployed and identified.

3-The anchor system was set up properly.

4-The anchor trench and liner placement were both done appropriately.

5-Welding equipment that was appropriate for the job was employed.

6-The quality control equipment was in good working order.

7-Extrusion welding seaming and/or fusion welding seaming were both verified.

8-All of the repairs have been done.

9-Pipe penetration must be done correctly.

10-The seams were perfectly aligned.

11-The installation was completed by the original plan.

12-The installation’s paperwork was completed.

Quality control is a requirement that must be met before, during, and after the project is completed.

To follow the progress of the work, as well as the difficulties encountered and how they were resolved, detailed records are kept.

A field manager then reviews these documents, giving an additional layer of quality assurance scrutiny.

Geomembrane Rolls / Panels Positioning

Individual panels/sheets are positioned using machines and/or by hand.

It’s important to take extra precautions to avoid damaging the lined surface.

Panel overlaps are corrected once the geomembrane is unrolled to provide a sufficient lap for the welding process.

Any damage to the geomembrane is examined before, during and after welding.

Geomembranes Works are limited by Environmental Conditions

Welding cannot be done at temperatures below 0°C or over 40°C, or in wet environments, since they will compromise the welding process’ integrity.

Geomembrane deployment amid high winds might be hazardous.

If the wind speed surpasses 20 mph, the installation process may be halted.

Rolls / Panels Joining

Wide wedge with an open-air channel, extrusion welding, and hot air for plastics.

The hot platen vulcanizing technique is used for rubbers.

All welds are thoroughly examined and tested.

Weld Joints are put to the test.

Each weld is put through a non-destructive examination by our workers.

The following are the test procedures:

1-The joint is air pressure checked before wedge welding.

2-The junction is spark-checked for extrusion.

3-Vulcanized joints are examined using an air lance or a vacuum box.

The mechanical characteristics of welded connections are checked for destructive testing by obtaining samples of a junction from an installation in progress and assessing the welds’ bonding strengths in tensile and peel.

References

[1] Geomembrane Explained, 24 June, [online] available at: https://industrialplastics.com.au/geomembrane-explained/.

[2] Geomembrane, [online] available at: https://komitexgeo.com/catalog/geomembrane.

[3] HDPE High-Density Polyethylene Geomembrane, [online] available at: https://www.naylor.co.uk/catalogue/hdpe-high-density-polyethylene-geomembrane/

[4] HDPE Liner, [online] available at: https://www.layfieldgroup.com/geosynthetics/geomembrane-liners/hdpe-liner.aspx

[5] LDPE Geomembrane – Convenient and Fast construction, [online] available at: https://www.geotextile-fabrics.com/products/geomembrane/ldpe-geomembrane.html

[6] Geomembrane Installation, [online] available at: https://www.enviroseal.co.uk/geomembrane-installation/

[7] ISO 9001: Guidelines for Installation of Flexible Geomembranes, [online] available at: https://www.butylproducts.co.uk/iso-9001-guidelines-for-installation-of-flexible-geomembranes/