Continuous filament geotextiles are now becoming well known features in many diverse civil engineering, road building and landscaping applications where high durability products are specified. As the name implies, compositions are made up of continuous filaments, whereas the older styles of geotextiles were manufactured from discrete fibres, with many obvious weak points in the finished fabric. A closer look tells us that the separation of fibre ends in a finished fabric made using the older technique has many disadvantages. Continuous filament geotextiles do away with these properties allowing total uniformity of strength across the face of the structure, superior resistance to puncture and have more resistance to destruction from abrasion when in use, thereby making this style of fabric ideally suited for use in highways, embankments, filters and elsewhere finally placed types of construction.
The measure of a geotextiles resistance to tension is termed Tensile Strength in which the test material is fabricated and pulled apart until breakage occurs, testing the strength of the material.
Continuous filaments are uniquely better at distributing stress evenly, without locally weakening the fabric; tensile strength lends itself well to the market where, for example, subgrade stabilisation and recovery of existing road surfaces is required. Here, the geosynthetic will support the traffic loads, over long periods.Improved Puncture Resistance
Resistance to puncture is another desirable characteristic of geotextiles. Continuous filament geotextiles are resistant to penetration by sharp objects such as stones or debris. The long, continuous fibers are entangled with one another to form a fabric that effectively spreads out the force of the penetrating object across the fabric.
This characteristic makes continuous filament geotextiles ideal for use in drainage and filtration layers. They are able to withstand impact and prevent soil particles and sand from passing through. This increases both the service life of both the geotextile and surrounding works.
Maintenance of Filtration Rate Characteristics
Strength and resistance to impact are not the only characteristics that may be of interest in a durable geotextile. Maintaining the permeable and filtration rates throughout the life of the project is also critical. Continuous filament geotextiles are able to provide a reasonable and consistent rate of permeability and filtration. Unlike the staple fabric previously described that may become clogged, the continuous filament retains an open void space to permit the passage of water while filtering out fine soil from passing through.
For use in drainage trenches, filtration or channelling application or even beneath the clay liner of an earthfilled retaining wall and landfill, the continuity of flow at a steady rate promotes unwanting soil erosion and setttlement effects that may render the works unserviceable.
UV Resistance
In locations where the geotextile is to be used relatively exposed or as in all roofing application prolonging sunshine exposure to ultraviolet rays, UV resistant fabrics may be of relevance. The continuous filament geotextile can be treated to prevent degradation of the fibre caused by UV rays.In short, the user of such infrastructure will benefit from longer life and evasion of expensive maintenance.
Greater Resistance to Chemical and Biological Assault
As the continuous filament geotextile is manufactured of polymers not sustaining chemical or biological attack, then likewise geocomposites making use of either polypropylene or PET fibres continue to brave out storm, acid and alkali for many years in use. In a severe environment of moisture, chemical attack, and biological exposure, such as a drainage run, rootstock project or landfill cap, and uncompromising terrain, the geocomposite remains of the same nature without threat to bearing power or filtrative success.
Successful Spotting for Use In Separation Layers
Seperation layers in the sub-base of roads and embankment applications are another field where geocomposites of continuous filament can do duty by preventing the mixing of the soil to achieve stability and a long life spell. In a geotextile today, a geocomposite spot placed as an adequate separation layer will pay dividends in avoiding of failure in soil deformation under traffic load and in injecting life into surfed road or embankment.
Inputs to Driveway and Landscaping Fabrics
Continuous filament geotextiles are also marking a major inroad into the driveway and landscaping fields, acting as an agent to stabilization of vehicular weight on gravel and tarmacadam layer. Continuous filament itself is tough enough to fend off soil rutting and displacement, but it will act too as an effective filter and drainage layer. By rejecting the UV it is possible that it has life and longevity in mind and this thinking is naturally apparent in landscape overgrowth for zero maintenance.
Performance raw criteria that really count
A geotextile with a continuous filament core will be tested on tapes for:
- Tensile Strength/ Load bearing capacity
- CBR Puncture Strength/ Puncture resistance
- Permeability/ Flow rate
- UV resistance
- Chemical attack
- All in the successful completion of durable environmental application.
Conclusion
Continuos filament geotextiles promote a long life through a mixture of high tensile strength, puncture resistant, and unassailable dilutability thus consorting well as the cloths themselves survive the attack of climate and chemical.