Woven & Non-woven Geotextile Fabric

HISTORY OF GEOTEXTILES

Prior to 1988, geotextiles was called plastic filler cloth or filter fabric. Because of the increase in the number of products being manufactured to be used as filter cloth, the specifications were revised. This material is now identified as Geotextile.

Geotextiles, an emerging field in the civil/construction engineering and other fields, offer great potential to utilize these fabrics in different areas of applications globally. Geotextiles are proving to be more cost-effective to traditional road construction methods. Fabric made are Woven, needle punched, heat bonded, Non-Woven, integrated loops or tufted loops Geotextiles are robust, permeable and durable fabrics. These fabrics have the ability to separate, filter, reinforce, protect, or drain and is designed to increase soil stabilization and ground support in a given location. Typically made from polypropylene or polyester or jute fibers/yarns. These geotextiles are high in strength to allow for maximum slope support, stabilization and erosion control. Geo fabric options include a felt-like nonwoven fabric as well as a woven polypropylene, synthetic or jute geotextile. Furthermore, the design of a geotextile is of paramount importance for any civil engineering application.

Families of Geotextiles

Geotextile composites have been developed and introduced products such Geotextiles, Geogrids, geonets, geomembrane, geosynthetic clay liners, geo pipes and geocomposites can yield benefits in geotechnical and environmental engineering design. Geotextiles and related products. Mostly geotextiles are placed at the tension surface to strengthen the soil. A large sand-filled container (SFC) within the dune system prevents storm erosion from proceeding beyond the SFC. Using a sloped unit rather than a single tube eliminates damaging scour.

Design features of geotextiles to retain properties

• Durability
• Absorbency
• Appearance

Expected serviceability of Geotextiles.

1. Reliable long-term performance
2. Should extend the service life of roads and highways
3. Ensures permanent load-carrying capacity
4. High-performance drainage systems
5. Foundation reinforcement of roads, railway tracks, runways

Geotextile Applications

Geotextiles and related products have many applications and currently support many civil engineering applications including roads, airfields, railroads, embankments, retaining structures, reservoirs, canals, dams, bank protection, coastal engineering, and construction site silt fences or geotube. Usually, geotextiles are placed at the tension surface to strengthen the soil. Geotextiles are also used for sand dune armoring to protect upland coastal property from storm surge, wave action, and flooding.

Use this chart to determine which type and weight of geotextile are best for your project.

Selection of appropriate geotextiles based on the type and weight of specific projects

Geotextiles usage chart

IMPORTANT CHARACTERISTICS OF GEOTEXTILES

The characteristics of geotextiles are broadly classified as:

• Physical properties:
  • specific gravity
  • weight
  • thickness
  • stiffness
  • density.
• Mechanical properties:
  • tenacity
  • tensile strength
  • bursting strength
  • drapability
  • compatibility
  • flexibility
  • tearing strength
  • frictional resistance
• Hydraulic properties:
  • porosity
  • permeability
  • permittivity
  • transitivity
  • turbidity /soil retention
  • filtration length etc.
• Degradation properties:
  • biodegradation
  • hydrolytic degradation
  • photodegradation
  • chemical degradation
  • mechanical degradation
  • other degradation occurring due to the attack of rodent, termite etc.
• Endurance properties:
  • elongation
  • abrasion resistance
  • clogging length and flow etc.

(For international standards refer ASTM.)

When using geotextiles, consider the following.

1. What has been the past performance of geotextiles in similar types of soil?
2. You will need to know solid characteristics and the permeability of the subgrade and match them to the permeability criteria of the geotextile.
3. Select the fabric strength requirements on the basis of constructability. More specifically, it must withstand placement and survive the construction period without puncturing, tearing, bursting, abrading, etc. Is the fabric sufficiently workable for the specific application? That is, can the geotextile support the workers and equipment during gravel placement.
4. Use standard load guidelines for designing pavement strength with no allowance for the geotextile.
5. In an existing roadway, check to see if additional subbase was added previously for extra structural support to counter the soil weakness and reduce rutting under construction equipment to three inches. If so, reduce that subbase by 39%-50% and include a geotextile in the design between the subgrade and subbase.
6. Select the cover carefully. If you will be applying for a surface course, you may use a cleaner aggregate with less than 15% fines. If this will be a gravel road and traffic will travel directly on the aggregate, then you must provide more fines (at least 15%) or the aggregate will whip off the fabric.