What do the thickness, impermeability and chemical resistance of geomembrane mean?

Chemical Resistance of Geomembranes

The chemical resistance of a geomembrane refers to its ability to remain stable and undamaged when exposed to different chemicals. Since the geomembrane may be exposed to various chemical substances in actual use, such as acids, alkalis, solvents, etc., its chemical resistance is very important.

Generally speaking, the polyethylene (PE) material used in geomembranes has good chemical resistance. The following are the effects of some common chemicals on geomembranes:

Acids: Geomembranes generally have good resistance to mild and neutral acids, but may be sensitive to concentrated and oxidizing acids.

Alkali: Geomembranes generally have good alkaline resistance and can withstand a certain concentration of alkaline media.

Solvents: Geomembranes have a certain tolerance to common organic solvents, such as alcohols, ketones and ethers.

It is worth noting that different types of polyethylene geomembranes may vary in their chemical resistance. In addition, geomembranes may also be affected by penetration, dissolution, swelling, deformation or loss of some physical properties under long-term exposure to chemical substances or special environments.

Therefore, when choosing a suitable geomembrane in an actual project, it is necessary to fully understand the chemical environment and chemical substances faced by the project, refer to relevant standards and specifications, and consult professionals for specific evaluation and suggestions.

The impermeability of geomembrane

It means that the geomembrane can effectively prevent water or other liquids, gases and other substances from penetrating from the bottom of the geomembrane to the top or vice versa.

Geomembranes are usually made of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC) and other materials, which have good anti-permeability. Its impermeability can be evaluated by the following two aspects:

Permeability coefficient: The permeability coefficient of the geomembrane indicates the ability of a unit area of liquid to pass through the geomembrane per unit time. A high-quality geomembrane should have a low coefficient of permeability, that is, less permeable to water and other liquids.

Impermeability pressure: The impermeability pressure of the geomembrane refers to the liquid pressure it can withstand, that is, the geomembrane will not rupture or leak under a certain pressure. A high-quality geomembrane should have sufficient anti-seepage pressure to ensure a long-term and stable anti-seepage effect in the project.

The anti-permeability of geomembrane is also related to the thickness of geomembrane, material quality, construction technology and other factors. In actual engineering, it is necessary to select the appropriate type and specification of geomembrane according to the specific engineering conditions, environmental requirements and design standards, and carry out correct construction and installation to ensure the expected anti-seepage effect.

Geomembrane Thickness

Geomembrane thickness refers to the vertical dimension of the geomembrane, usually expressed in millimeters (mm) or microns (μm). Choosing the appropriate thickness of geomembrane has an important impact on the performance and life of the project.

The thickness of geomembrane is generally determined according to the requirements and design standards of specific projects, considering the following factors:

Soil conditions: The soil properties and bearing capacity of different regions are different, and the corresponding geomembrane thickness needs to be selected according to the actual situation. For example, in firmer soils, a thinner geomembrane may be used; in loose or leak-prone soils, a thicker geomembrane may be required.

Project type: Different types of projects, such as pools, dams, roadbeds, etc., have different anti-seepage requirements for geomembranes. Generally speaking, for high-demand hydraulic projects or environmental projects, it is necessary to choose a thicker geomembrane to ensure the anti-seepage effect.

Expected service life: The thickness of the geomembrane is closely related to its expected service life. Thinner geomembranes may be suitable for temporary projects or short-term use, while for long-term projects, in order to ensure a long-lasting anti-seepage effect, it may be necessary to choose a thicker geomembrane.

It should be noted that when choosing the thickness of the geomembrane, factors such as cost, construction feasibility and project sustainability should also be considered comprehensively. The optimum geomembrane thickness should be determined through professional engineering design and evaluation to meet the specific needs and requirements of the project.