What are the characteristics of composite geomembranes?

After the pressure head on both sides of the composite geomembrane reaches a certain value, the composite geomembrane will rupture. When the seepage rate increases rapidly, it means that the sample is damaged, and the hydrostatic pressure resistance value of the sample is obtained. Maintain the above pressure of the composite geomembrane for at least 2h, observe the change of the water level of the seepage pipe, the water level of the composite geomembrane is basically stable (the seepage rate is 0), then increase the pressure step by step for the gradation difference, and each stage is maintained for 2h until the seepage rate increases rapidly, indicating that the sample has been ruptured, and the previous pressure is used as hydrostatic pressure (MPA).

If the composite geomembrane only needs to determine whether the geomembrane sample reaches a certain specified hydrostatic pressure resistance value, it can be directly pressurized to this pressure and maintained for 2 hours, and then judged to meet the requirements. At least 3 samples of each sample of the composite geomembrane are measured, and the lowest value is used as the hydrostatic pressure resistance of the sample. Characteristics of warp knitted composite geomembrane:

High tensile strength, low elongation, uniform longitudinal and transverse deformation, high tear strength, excellent wear resistance, and strong water barrier. Warp knitted composite geomembrane. <>

Composite geomembrane is widely used in channel seepage prevention engineering. In recent years, a large number of applications and effects of geosynthetics in civil engineering, especially in flood control and rescue projects, have attracted great attention from the majority of engineering and technical personnel. For the application technology of geosynthetics, the state has put forward normative technical requirements from the aspects of seepage, filtration, drainage, reinforcement and protection, which has greatly accelerated the pace of promotion and application of new materials.

The material has been widely used in the anti-seepage engineering of irrigation canals, combined with construction practice, and the application technology of composite geomembrane. Composite geomembrane is made of impermeable material composed of geotextile and geomembrane, it is mainly used for impermeability, composite geomembrane is divided into one cloth and one membrane and two cloth and one membrane, width of 4-6m, weight of 200-1500g m2, tensile resistance, tear resistance, bursting and other physical and mechanical properties are high, can meet the needs of water conservancy, municipal, construction, transportation, subway, tunnel and other civil engineering. Due to the selection of polymer materials and the addition of anti-aging agents in the production process, it can be used in unconventional temperature environments.

Composite geomembrane (composite impermeable membrane) is divided into one cloth and one membrane and two cloth and one membrane, with a width of 4-6m and a weight of 200-1500g square meters, with high physical and mechanical properties such as tensile resistance, tear resistance and bursting, and the product has the characteristics of high strength, good elongation performance, large deformation modulus, acid and alkali resistance, corrosion resistance, aging resistance, and good impermeability performance. It can meet the needs of civil engineering such as water conservancy, municipal, construction, transportation, subway, tunnel, and engineering construction such as seepage, isolation, reinforcement, and anti-cracking reinforcement. It is often used for anti-seepage treatment of dams and drainage ditches, as well as anti-fouling treatment of waste yards.

The composite geomembrane is heated by the far infrared of the oven on one or both sides of the film, and the geotextile and the geomembrane are pressed together by the guide roller to form a composite geomembrane. With the improvement of the production process, there is also a casting method to do the process of composite geomembrane. Its form is one cloth and one film, two cloth and one film, two films and one cloth, etc.

As the protective layer of the geomembrane, the geotextile protects the impermeable layer from damage. In order to reduce ultraviolet radiation and increase anti-aging performance, it is best to use the embedded method.

Composite geomembrane is an impermeable material made of geotextile and geomembrane, which is mainly used for anti-seepage drainage and reinforcement. The composite geomembrane is divided into one cloth and one membrane, two cloth and one membrane, and multiple cloth and multiple membranes. The width is 1-6m, the weight is m2, and the physical and mechanical properties such as tensile resistance, tear resistance, and bursting are high, which can meet the needs of water conservancy, transportation, environmental protection, municipal, construction, tunnel and other projects.

Due to the polymer material used in the base and the addition of anti-aging agents in the production process, it can be used in unconventional temperature environments.

Product features: 1. It integrates anti-seepage, reverse filtration and drainage, and has the functions of isolation and reinforcement.

2. High composite strength, high peel strength and high puncture resistance.

3. Strong drainage capacity, large friction coefficient and small expansion coefficient.

4. Good aging resistance, wide range of environmental temperature and stable quality.

Scope of application: widely used in water conservancy, environmental protection, construction, transportation, tunnels and other projects.

Geomembrane series.

Function: anti-seepage, isolation.

Uses: River embankments, lake dams, tailings dams, sewage dams and reservoir areas, channels, reservoirs (pits, circles) Metro, basement and tunnel, tunnel seepage lining.

Roadbed and other foundations are salted and impermeable.

Horizontal anti-seepage covering in front of embankments and dams, vertical impermeable layer of foundation, construction cofferdam and waste yard.

Marine and freshwater aquaculture farms.

roadbeds for highways, highways, railways; Waterproofing layer of expansive soil and collapsible loess.

Roofing impermeability.

The covering part must be leveled, and a transition layer with a thickness of about 30cm and a maximum particle size of 20mm for the composite geomembrane must be laid. A filter layer is also laid on the membrane, followed by a protective layer. The perimeter of the membrane should be tightly combined with the impervious layer of the bank slope on both banks.

The connection between the impermeable film and the anchoring groove is determined by the allowable contact penetration slope between the film and the concrete. PVC and butyl rubber films can be well adhered to the concrete surface with adhesives or solvents, so the embedding length can be shorter. Because the polyethylene film cannot adhere to the concrete surface, the length of the embedded concrete is at least.

Geomembranes are geosynthetics with very low water permeability. In order to make the film play its due impermeable role, in addition to the requirement that the film itself is impermeable, it is also necessary to pay attention to the construction quality of laying the impermeable film.

1) The connection between the impermeable membrane and the perimeter boundary. The impermeable membrane must be tightly bonded to the perimeter boundary. During construction, the foundation and the bank slope can be excavated and connected by anchor grooves.

If the foundation is a shallow sand and gravel permeable layer, the sand and gravel should be excavated to the bedrock, and the concrete base should be poured quickly to fix the geomembrane in the concrete; If the foundation is impervious to the clay layer, the anchor groove with a depth of 2m and a width of about 4m can be excavated, and the geomembrane can be placed in the groove, and then the clay can be densely backfilled; If the foundation is a deep sand and gravel permeable layer, it can be prevented by using the polishing brigade method of geomembrane covering, the length of which is determined according to the calculation.

2) The contact surface between the impermeable film and the supporting material should be smooth, so as to avoid the film being punctured and losing its anti-seepage effect. Otherwise, a fine-grained cushion should be installed to protect the film from damage.

3) The impermeable membrane itself is connected. The connection method of impermeable film can be summarized into three types, namely bonding method, welding method and vulcanization method. The impermeability of all joints should be checked, and the geomembrane should be laminated to prevent leakage due to poor joint connection.

Abstract:Composite geomembrane is a kind of impermeable geotechnical material, there are a variety of different standards, the composite geomembrane on the market generally has three kinds of national standard, urban construction standard and American standard, and there are some non-standard geomembranes made of first-class materials. The requirements of the national standard geomembrane and the cover with the American standard geomembrane are higher, which are the two commonly used in the market, and the American standard has higher performance requirements than the two standard geomembranes.

Let's take a look at the difference between the American standard geomembrane and the national standard geomembrane. 1. What are the standards for composite geomembranes?

Geomembrane is a kind of waterproof barrier material with polymer as the basic raw material, which is widely used, and there are many geomembrane products on the market, with a number of different standards. At present, there are three main types of geomembranes: national standard, urban construction standard and American standard

1. National standard. GB T17642-2008 Geosynthetics, Nonwovens, Composite Geomembranes.

GB T17643-2011 Geosynthetics: Polyethylene geomembrane.

2. Urban construction standards.

CJ T234-2006 High-density polyethylene geomembrane for landfill.

CJ T276-2008 Linear low-density polyethylene geomembrane for landfill.

3. American Standard. astm-grigm13

In addition, there are some non-standard geomembrane products on the market, which are made of recycled materials, which are cheaper, but the performance is relatively poor.

2. What is the difference between the American standard geomembrane and the national standard geomembrane?

There are certain differences in the performance of Zhengzheng geomembranes of different standards, but the test items are almost the same, including yield elongation, elongation at break, tensile yield strength, puncture resistance, dimensional stability, ultraviolet aging resistance, density, impurities, carbon black content, etc., the difference between the national standard and the American standard of geomembrane is that the requirements of these test items are different.

Relatively speaking, the testing standard of the American standard geomembrane is higher than the national standard, and the technical requirements of the American standard geomembrane are 12% yield elongation, 700% elongation at break, and more than 300h resistant to environmental stress cracking, etc., which is difficult to achieve in the general calendering process, so the service life and ** are much higher than those of other standard geomembranes.

However, the new national standard also classifies the indicators of HDPE geomembrane, which are divided into ordinary type and environmental protection type, and the requirements of the national standard environmental protection geomembrane are close to the American standard.

Geomembrane is a simple layer of polyethylene plastic film, while composite geomembrane refers to two cloth and one membrane or one cloth and one membrane, and multiple cloth and multiple membrane composite geomembranes. Both have the characteristics of anti-seepage and isolation.

The anti-seepage effect of the composite geomembrane is safer and more stable, because both sides or one side are geotextiles, which can protect the geomembrane from being damaged and strengthen the service life of the project. The use of the two is different, the geomembrane is more extensive, while the composite geomembrane is used in artificial lakes, reservoirs, landfills design more stringent projects.

Geomembrane is a kind of plastic membrane that can play an impermeable role, generally speaking, the geomembrane is made of polyethylene particles, according to the different materials, the geomembrane can be divided into HDPE geomembrane (high-density polyethylene geomembrane), LDPE geomembrane (low-density poly.

ethylene geomembrane), LLDPE geomembrane (linear low-density polyethylene geomembrane). Geomembranes are mainly used in engineering seepage prevention, such as:

Landfill seepage, solid waste landfill seepage, tailings treatment site seepage, sewage treatment site seepage, power plant regulating pond seepage prevention,

Anti-seepage of reservoirs, anti-seepage of rainwater collection tanks, anti-seepage of oil storage tank foundations, anti-seepage of chemical reaction tanks, anti-seepage of washing tanks, anti-seepage of heap leaching tanks

Ash pond seepage prevention, dissolution tank seepage prevention, sedimentation tank seepage prevention, breeding pond seepage prevention and other projects.

Composite geomembrane refers to a geomembrane with geotextiles bonded on two sides or one side. It is specifically divided into two cloths and one film or one cloth and one film. Composite geomembranes are generally used for seepage prevention in water conservancy projects. For example: river seepage prevention, artificial lake seepage prevention, reservoir seepage prevention, canal seepage prevention, wetlands.

Anti-seepage, highway and railway subgrade seepage prevention and other projects.

The above is an introduction to the difference between geomembrane and composite geomembrane and the introduction of the site used in geomembrane and composite geomembrane.

There are three types of composite geomembranes, 1. Two cloths and one membrane are like Oreos, and a layer of geomembrane is sandwiched between the two layers of cloth.

2. A cloth and a film are like breaking the half of the Oreo with the cream, a layer of cloth and a layer of geomembrane.

3. If you have more cloth and more films, you need to see how many layers of cloth and several layers of film you need, in short, it must be a cloth film, a film and a cloth, it will not be two layers of cloth glued together, nor will it be two layers of film glued together.

The composite geomembrane is fooling foreigners, there is no standard at all, it is recommended that you use HDPE geomembrane.

Geomembrane is a light** HDPE composite geomembrane with one cloth and one membrane and two cloth and one membrane.

Composite geomembrane (referred to as geomembrane) is also called impermeable geotextile, which usually refers to the synthetic material formed by bonding geotextile (woven fabric or plastic woven cloth) and PE film. It is divided into one cloth and one film and two cloth and one film, with a width of 4-6m and a weight of 200-1500g square meters, with high physical and mechanical properties such as tensile resistance, tear resistance, and breakage, and the product has the characteristics of high strength, good elongation performance, large deformation modulus, acid and alkali resistance, corrosion resistance, aging resistance, and good anti-seepage performance.

The specific functions of composite geomembrane are:

1. The composite geomembrane is suitable for water conservancy. Such as the seepage prevention, plugging and reinforcement of rivers, lakes and reservoirs, the seepage prevention of canals, vertical core walls, slope protection, etc.

2. Composite geomembrane can be used for environmental protection and environmental sanitation. Such as landfills, sewage treatment plants, power plant regulating tanks, industrial, hospital solid waste, etc.

3. Composite geomembranes can be used in gardens, artificial lakes, rivers, reservoirs, pond bottoms of golf courses, slope protection, waterproof and moisture-proof green lawns.

Fourth, municipal engineering, subway, building underground engineering, planting roof, roof garden seepage, sewage pipeline can also use composite geomembrane.

5. The composite geomembrane is suitable for mining, washing ponds, heap leaching ponds, ash dumps, dissolving ponds, sedimentation tanks, stockpiles, tailings bottom lining seepage prevention, etc.

6. Petrochemical, chemical plants, refineries, oil storage tanks for seepage prevention, chemical reaction tanks, sedimentation tank lining, secondary lining, etc. can still use composite geomembranes.

7. Composite geomembrane is also used in aquaculture, intensive, factory breeding ponds, fish ponds, shrimp pond lining, sea cucumber circle slope protection and other fields.

8. Salt industry, salt field crystallization pool, brine pond cover, salt film, salt pond plastic film.

9. In agriculture, reservoirs, drinking water pools, reservoirs, irrigation systems, etc., Henan Kangxi Technology composite geomembrane is also widely used.

10. Transportation facilities, highway foundation reinforcement, culvert seepage prevention can be constructed with composite geomembrane.