- the oldest and most commonly used geosynthetic today - are engineered to provide cost-effective solutions to meet specific design requirements.
And although there are at least 80 specific 'applications' for geotextiles that have been developed, a geotextile always performs at least one of
five discrete 'functions':
Carthage Mills developed and pioneered the first use of geotextile fabrics in 1958. Originally
termed "filter fabrics" or "plastic filter cloths", they were all
Until 1967 Carthage was alone in its efforts and had the only plastic filter cloths available on the market. But it was Carthage Mills'
innovative designs and techniques of construction (many of which are still used today), and the successful performance of those first applications of
plastic filter cloths that helped to launch the geosynthetics 'industry' as we know it today (See
Geosynthetics: How it all began
Geotextiles are often defined as: geotextile, n: A permeable textile manufactured from polymeric material used with foundation, soil, rock or any other geotechnical
engineering-related material as an integral part of, and to enhance the performance or cost of, a human-made product, structure, or system.
Although geotextiles are textiles in the traditional sense, because they consist of synthetic materials, biodegradation is not a problem. The fibers and/or yarns used
in the manufacture of geotextiles are made from the following polymeric compounds, listed in order of decreasing use: polypropylene, polyester, polyamide, and
polyethylene. However, the major point is they are porous to water flow both across and within their manufactured plane, but to a widely varying degree.
Classifications or Types of Geotextile Fabrics
There are a seemingly endless combinations of polymers, yarns, fibers and manufacturing processes that produce the three major geotextile classifications: woven,
nonwoven and - to a lesser degree - knitted. In general:
Woven geotextiles consist of monofilament, multifilament, slit-film and/or fibrillated slit-film yarns - often in
combinations - that are woven into a geotextile on conventional textile weaving machinery using a wide variety of traditional, as well as proprietary,
weaving patterns. The variations are many and most have a direct influence on the physical, mechanical and hydraulic properties of the fabric. The resulting
woven geotextiles are typically flexible, exhibit high strength, high modulus, low elongation, and their openings are usually direct and predictable.
Nonwoven geotextiles consist of fibers that are continuous filament or short staple fibers. These fibers are then
bonded together by various processes that can include a needling process that intertwines the fibers physically (needlepunched), or a chemical / thermal bonding
operation that fuses adjacent fibers together. The resulting nonwoven geotextiles have a random fiber orientation with high porosity and permeability, but
indirect and unpredictable openings, a thickness ranging from thick felt to a relatively thin fabric, and low modulus and high elongation (needlepunched).
American Association of State Highway and Transportation Officials and AASHTO: M288-15
A joint committee, formed from the American Association of State Highway and Transportation Officials (AASHTO) and the Industrial Fabrics Association (IFAI),
developed a general platform to standardize geotextiles for general transportation applications. The current revision for this standard is AASHTO: M288-15.
AASHTO: M288-15 is NOT a design guideline. The selection criteria are based on an engineer's knowledge of the site-specific installation stresses and soil
hydraulic properties for the project application.
Click here for a Geotextile Selection Guide
and the appropriate Carthage Mills product. For further information on Carthage Mills and AASHTO: M288-15 contact your local Carthage Mills Representative
or call (800) 543-4430. To order a copy of the complete AASHTO: M288-15 Specification, contact AASHTO at (202) 624-5800.