by What is it?
Geomembranes are synthetic membrane liners used in construction for purposes like providing barriers, containment and protection. Made of materials like high-density polyethylene (HDPE), polyvinyl chloride (PVC), ethylene propylene diene monomer (EPDM) and polypropylene (PP), geosynthetic are commonly used to line man-made structures for moisture sealing, drainage and as barriers against chemicals. The material’s chemical resistance, low permeability and flexibility make them useful for a variety of applications.
Uses of Geosynthetic in Construction
Landfill Liners
One of the most common uses of geosynthetic is in landfill liners. As landfills collect waste under layers of soil or rock, moisture barriers are needed to prevent leachate from contaminated water seeping into soil and groundwater. Geosynthetic provide high strength barriers underneath landfill sites. The multilayer linings composed of geosynthetic and soil protect the environment from contaminants in leachate.
Water Containment Structures
Other types of structures where geosynthetic are used are water containment systems like mining tailings ponds, agricultural and livestock waste lagoons, and aquaculture and fish farms. Geosynthetic are installed at the bottom and sides of these structures to prevent leakage and seepage of liquids into surrounding soil and groundwater. Their chemical resistance makes them suitable for containment of industrial effluents and wastewater as well.
Road Infrastructure
In road construction, geosynthetic are used as waterproofing barriers under highways to prevent water from saturating roadbase layers and subgrade soil. They are also used in separation geotextiles between roadbase and subgrade to prevent mixing of layers. Geosynthetic find increasing application in canal and dam lining where they provide a flexible, jointless barrier against leakage.
Mining Applications
Another major end-use of Geomembranes is in mining applications. They are used to line storage areas and containment ponds for mining waste and by-products. In surface mining, geosynthetic are installed under areas with high risks of acid rock drainage or metal leaching to safeguard nearby water sources. During mineral extraction and underground mining, geosynthetic waterproof tunnel walls as a supportive ground treatment.
Benefits of geosynthetic
Cost-Effectiveness
While initial installation costs of geosynthetic may be high compared to compacted clay, they provide significant life cycle cost benefits. Geosynthetic last over 50 years with minimum maintenance and do not require replacement like clay liners. They save costs of lost contaminants, groundwater remediation and also avoid legal penalties of environmental contamination. Overall, geosynthetic deliver greater long term cost-effectiveness than traditional earthen barriers.
High Impermeability
Geosynthetic have very low permeability to liquids and gases compared to soil and clay. Even microscopic defects do not impact their impermeability much. This attribute makes them extremely effective at containing contaminant movement. Their permeability is usually several orders of magnitude lower than required standards for liners.
Conformability and Flexibility
Geomembranes can easily conform to uneven and irregular substrate surfaces without tearing. They flex with soil movement without compromising integrity. This allows installation over rock contours and in applications with settling and subsidence issues. The sheets can be heat-welded for a continuous seamless liner unaffected by cracks in subgrade.
Chemical Resistance
Different geosynthetic polymers offer excellent resistance to a wide range of aggressive chemicals depending on application. While PVC resists acids/bases and HDPE withstands non-aromatic hydrocarbons, other materials like PP and HDPP hold up against a variety of inorganic/organic substances. This durability protects containment from hostile industrial leachates and waste.
Sustainability
Proper installation and maintenance of geomembranes ensure complete containment during project lifespan without any contamination risk. They present a safer solution for the environment compared to unlined earthen barriers. Reusable after project decommissioning, geosynthetic s make facilities more sustainable and environment-friendly over long term.
Disadvantages
While geosynthetic deliver compelling advantages for construction projects, some potential disadvantages also need consideration:
– Higher initial costs than compacted clay liners
– Require competent subgrade preparation for maximum performance
– Prone to damage during installation/backfilling if not handled properly
– Susceptible to defects from roots, stones and construction activity
– Mostly non-biodegradable so require careful disposal after service life
Quality Checks for Successful Implementation
For geosynthetic to achieve their designed functions, quality assurance checks are essential during four critical stages – manufacturing, transportation, installation and post-construction. Regular testing ensures no defects, proper material properties, standardized installation techniques and long term durability. Manufacturers must adhere to governing quality standards and provide certification. Competent installers, thorough inspection protocols along with suitable protective/remediation layers over geosynthetic further guarantee barrier effectiveness.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
