Non-woven geotextile construction technical requirements
Non-woven geotextiles are widely used in civil engineering and construction projects for their filtration, separation, drainage, and reinforcement properties. The technical requirements for non-woven geotextile construction can vary based on the specific application and project needs, but generally, the following criteria are considered:
1. Material Composition
Polymer Type: Typically made from polypropylene or polyester fibers due to their chemical resistance, durability, and stability.
Additives: UV stabilizers and other additives may be included to enhance durability and performance.
2. Physical Properties
Weight: Usually measured in grams per square meter (g/m²). Common weights range from 100 to 600 g/m², depending on the application.
Thickness: The thickness can vary but generally ranges from 1 to 10 mm. It’s chosen based on the required strength and filtration capabilities.
3. Mechanical Properties
Tensile Strength: Indicates the ability to withstand stretching forces. Typical values range from 5 to 50 kN/m.
Elongation at Break: Measures how much the material can stretch before breaking, usually expressed as a percentage. Non-woven geotextiles often have an elongation range of 20% to 100%.
Tear Resistance: The ability to resist tearing, important for durability during installation and use.
4. Hydraulic Properties
Permittivity: Indicates the water flow rate through the geotextile, typically measured in seconds⁻¹. Higher permittivity means better filtration and drainage capabilities.
Apparent Opening Size (AOS): Refers to the largest soil particle that can pass through the geotextile. It’s usually given in millimeters or sieve size.
Water Flow Rate: Measured in liters per square meter per second (l/m²/s) or similar units, indicating the volume of water the geotextile can transmit.
5. Chemical and Biological Resistance
Chemical Resistance: Ability to resist degradation from chemicals present in the soil or water.
Biological Resistance: Resistance to damage from biological agents such as fungi, bacteria, and insects.
6. Durability
UV Resistance: Protection against degradation from exposure to ultraviolet light. UV stabilizers are often added to enhance this property.
Abrasion Resistance: The ability to withstand surface wear and mechanical damage.
7. Installation Requirements
Roll Size: Typically comes in rolls for ease of transport and installation. Common widths range from 1 to 6 meters, with lengths up to 100 meters or more.
Seaming Methods: Can be sewn or bonded together if larger sheets are required. Seaming methods should be robust enough to maintain integrity during handling and use.
8. Standards and Testing
Compliance with Standards: Geotextiles should meet relevant national and international standards such as ASTM (American Society for Testing and Materials), ISO (International Organization for Standardization), or EN (European Norms).
Testing Requirements: Geotextiles should undergo rigorous testing for tensile strength, puncture resistance, permittivity, AOS, and other relevant properties.
Application-Specific Considerations
Filtration and Drainage: Focus on hydraulic properties to ensure proper water flow and soil retention.
Reinforcement: Emphasis on tensile strength and elongation properties to provide stability and support.
Separation: Balance between mechanical and hydraulic properties to maintain soil separation while allowing water movement.
By adhering to these technical requirements, non-woven geotextiles can effectively serve their intended functions in various civil engineering and construction applications.
Before laying the geotextile, the installation unit must provide the geotextile laying and anchoring connection plan. It is required to choose the laying direction reasonably, reduce the stress on the joints as much as possible, and reasonably arrange the position of each piece of material, and strive to ensure that the joints are at least on a slope greater than There shall be no transverse joints on the 10% slope surface and within 1.5m of the slope foot.
The material specifications and quality of the geotextile, the specifications and material properties of the sutures should comply with the design requirements and relevant standards.
The laying of geotextile should be smooth and free of damage and wrinkles.
When laying the geotextile, one end of the geotextile should be anchored on the slope first, and then the roll should be lowered along the slope to ensure that the geotextile remains taut.
The geotextile should be held down with sandbags at appropriate distances. The sandbags will be used during laying and retained until the top layer of material is laid.
When laying the geotextile, care must be taken not to allow stones, large amounts of dust or moisture, or other substances that may damage the geotextile, block the drainage system, or cause difficulty in subsequent connections, to enter the geotextile or underneath the geotextile.
While laying the geotextile, the installation unit shall take all necessary measures to prevent damage to the anti-seepage layer material below. The geotextile can only be cut with a geotechnical knife (hook knife). If it is cut on the site, other materials must be protected. Measures to prevent damage to the geotextile caused by cutting it.
The geotextile is connected by stitching, and the stitching is double stitching. The suture line must be made of the same or higher material than the geotextile material. The suture line must be made of chemical and ultraviolet resistant material.