Classification and application of polyethylene geomembrane

v Definition

Polyethylene geomemes (HDPE geomemes) are synthetic geomaterials made of high density polyethylene (HDPE) resin, mainly used in the engineering field of impermeability, isolation and waterproofing. It is manufactured by extrusion or blow molding technology, with excellent impermeability, strong mechanical strength, chemical resistance and long service life.

v Classification of polyethylene geomembrane

1. ClasClassification by material

1) High-density polyethylene geomembrane (HDPE geomembrane) : has good heat resistance and cold resistance, the use of a wide range of ambient temperatures, high temperature up to 110, low temperature to -70C. Excellent chemical stability, can resist the corrosion of strong acid, alkali, oil, high permeability coefficient, high mechanical strength, high tensile strength, can meet the needs of high standard engineering projects, is widely used in landfill, sewage treatment plants and other places.

2) Low density polyethylene geomembrane (LDPE geomembrane) : good flexibility, aging resistance and environmental stress cracking compared with HDPE geomembrane is better, often used in reservoirs, artificial lakes, irrigation systems and other areas with high flexibility requirements.

3) Linear low-density polyethylene geomembrane (LLDPE geomembrane) : It combines some advantages of HDPE and LDPE, has high strength and good flexibility, and is also widely used in some specific engineering fields, such as agricultural irrigation, aquaculture and so on.

4) Ethylene - vinyl acetate copolymer geomembrane (EVA geomembrane) : has good flexibility, low temperature resistance and puncture resistance, but also has a certain degree of elasticity, in some of the material flexibility and puncture resistance requirements of higher engineering applications, such as tunnel waterproof engineering, roof waterproof engineering.sification of polyethylene geomembrane

5) Composite polyethylene geomembrane

Composite geomembranes are usually polyethylene geomembranes and other materials (such as geotextiles) to comprehensively improve their mechanical properties, impermeability and chemical resistance. It is widely used in landfill, pond seepage prevention and water conservancy projects.

2. Classification by membrane surface state:

1) Smooth geomembrane: geomembrane with smooth and flat appearance on both sides. Its surface is smooth, the friction coefficient is small, and it is more suitable for application in some projects that need to reduce resistance or require higher surface smoothness, such as some special industrial plant floor waterproof and places that require surface cleanliness.

2) Rough geomembrane: a geomembrane with uniform rough appearance on one or both sides produced by certain technological means. Rough geomembrane can be divided into single rough surface and double rough surface, its surface roughness increases the friction coefficient with soil, sand and other materials, can effectively prevent the geomembrane in the use of sliding, enhance the bond between the geomembrane and the surrounding materials, especially suitable for water conservancy projects in DAMS, channels and other need good anti-slip performance of anti-seepage projects.

1.  Classification by color:

1) Black film: is the most common color, due to the addition of additives such as carbon black in the production process, so that it has good ultraviolet resistance and aging resistance, can extend the service life of geomemofilm, widely used in a variety of outdoor and long-term exposure to the sun in the anti-seepage project.

2) White film: has a high reflectivity, can reflect the heat in the sun, reduce the surface temperature of the geomemofilm, in some of the temperature control requirements of the project application is more suitable, such as greenhouse ground seepage, roof insulation and waterproof.

3) Other color film: such as green, blue and other color geomemes, mainly used for some projects with special landscape requirements or identification, such as park lakes, golf course water features, both to meet the impermeability function, but also to coordinate with the surrounding environment, play a role in beautifying the landscape.

2. Classification by quality standard:

1) Non-standard type: generally refers to polyethylene geomemographic products that do not meet national standards or industry standards, and their quality and performance indicators are relatively low, usually used for some temporary or small projects with low impermeability requirements and simple use environment.

2) National standard type: polyethylene geomemofilm produced and tested in accordance with national standards, quality and performance indicators meet the requirements of relevant national standards.

3) Urban construction type: on the basis of meeting the national standards, but also in line with the relevant standards and requirements of the Ministry of Construction geomemofilm products。

v Application field of polyethylene geomembrane

1. Field of hydraulic engineering

1) Reservoir dam: In the seepage prevention project of reservoir dam, polyethylene geomemofilm can be laid inside or on the surface of the dam body to prevent water leakage in the reservoir. 

2) Artificial lake and landscape pond: used for anti-seepage treatment of artificial lake and landscape pond bottom and bank slope. It can prevent the lake from leaking and keep the water level stable, thus reducing the cost of water refill.

3) Channel seepage prevention: In irrigation channels and water transmission channels, the laying of polyethylene geomemofilm can greatly reduce the leakage loss of water in the transportation process. In water-scarce areas, it can effectively reduce the waste of irrigation water.

2. Field of municipal engineering

1) Landfill: as the anti-seepage liner of the bottom and slope of the landfill, prevent the landfill leachate from penetrating into the groundwater and polluting the soil and groundwater environment. At the same time, geomembrane also plays an important role in the sealing and covering system of landfill, which can reduce the infiltration of rainwater into the garbage and reduce the production of leachate.

2) Sewage treatment plant: In sewage treatment facilities, such as regulating ponds, sedimentation ponds, anaerobic ponds and other pools, the inner surface of the geomembic film is laid to prevent sewage leakage, protect the surrounding soil and groundwater from pollution.

3) Underground integrated pipe gallery: used for the waterproof of the underground integrated pipe gallery to protect the various pipelines in the pipe gallery from the erosion of groundwater.

 3. Construction engineering field

1) Basement waterproof: It is applied in the outer wall and bottom waterproof layer of the basement of the building to prevent groundwater from penetrating into the basement.

2) Roof waterproof: As a new type of roof waterproof material, it can be used alone or combined with other waterproof materials. It also helps to save energy in buildings.

3) Tunnel waterproofing: In tunnel engineering, it is used for waterproofing behind the lining to prevent groundwater from penetrating into the tunnel and ensure the normal use and structural safety of the tunnel.

4. Traffic engineering field

1) Roadbed waterproofing: laying geomembrane at the bottom of the roadbed to prevent groundwater from rising and soaking the roadbed, thereby improving the stability of the roadbed. Especially in some soft ground sections, it is particularly important to prevent the erosion of ground water to the roadbed.

2) Railway roadbed waterproof: For railway roadbed, geomembrane can also play a waterproof role to ensure the stable operation of railway tracks. In the case of groundwater or poor geological conditions of subgrade, geomembrane can effectively isolate groundwater and avoid diseases such as uneven settlement of subgrade.

5. Agricultural field

1) Aquaculture pond: Laying geomembrane at the bottom and around the aquaculture pond can effectively prevent pond water leakage, maintain stable water quality and water level, and create a good environment for aquaculture. At the same time, geomembrane can also prevent harmful substances in the soil from dissolving into the water, affecting the growth of aquatic products.

2) Greenhouse: Laying geomembrane on the ground of greenhouse, on the one hand, can prevent soil water evaporation and maintain soil moisture; On the other hand, it can also prevent the invasion of underground pests and germs and reduce the occurrence of diseases and pests. In addition, in some modern soilless cultivation greenhouses, geomembranes can also be used as impermeable materials for nutrient solution pools.

v Summarize

Polyethylene geomembrane has a profound impact on the future of China and the world. In the world, it is widely used in landfills, tailings ponds, etc., can effectively prevent the leakage of harmful substances, protect soil and groundwater, and is of great significance for ecological protection. In water conservancy projects, the water loss of reservoirs and channels can be reduced and the utilization efficiency of water resources can be improved. In China, with the improvement of infrastructure construction and environmental protection needs, it is indispensable in the construction of sponge cities and the waterproof of underground integrated pipe corridors. At the same time, it helps to modernize agriculture, such as seepage prevention of breeding ponds and irrigation facilities. This material will promote the development of global environmental protection and infrastructure construction, improve the level of resource protection and utilization, and promote sustainable development.