- Geomembranes
Geomembranes are a kind of
geosynthetic material. They are impermeable membranes used widely as cut-offs and liners. Until recent years, geomembranes were used mostly ascanal andpond liner s.Current applications
One of the largest current applications is at
landfill sites for the containment of hazardous or municipal wastes and theirleachate s. [ [http://openurl.ingenta.com/content?genre=article&issn=0266-1144&volume=18&issue=1&spage=47&epage=61 Kodikara J. (2000) "Analysis of tension development in geomembranes placed on landfill slopes" "Geotextiles and Geomembranes" Volume 18, pp. 47-61(15)] ] In many of these applications geomembranes are employed with geotextile or mesh underliners which reinforce or protect the more flexible geomembrane whilst also acting as an escape route for gases and leachates generated in certain wastes.Composition
Geomembranes are made of various materials. Some common geomembrane materials are Low-Density
Polyethylene (LDPE), High-Density Polyethylene (HDPE),Polyvinyl Chloride (PVC),Polyurea and Polypropylene (PP). Another type of geomembrane is bituminous geomembrane, which is actually a layered product of glass and bitumem-impregnated non-woven geotextile.Characteristics
Each type of geomembrane material has different characteristics which affect installation procedures, lifespan and performance. For example, PVC geomembranes are very flexible and as a result can conform to uneven surfaces without becoming punctured. LDPE, on the other hand, is very susceptible to UV radiation, and therefore should not be used in applications where it will be exposed or else it will become brittle and fragile.
References
ee also
*
Hard landscape materials
Wikimedia Foundation. 2010.
