Textiles in
Geotextiles
Dr Muhammad Mushtaq Mangat www.mushtaqmangat.org
Geotextiles
Permeable fabrics which, when used in
association with soil, have the ability to separate, filter, reinforce, protect, or drain. geotextile fabrics come in three basic forms:
These are made from polypropylene or polyester,
woven (looks like mail bag sacking),
needle punched (looks like felt),
heat bonded (looks like ironed felt).
[http://en.wikipedia.org/wiki/Geotextile]
http://www.conhur.com/ geotextile.html
Start of modern geotextiles [1]
In the early 1960s and 1970s, some pioneering
engineers wondered if textiles conditions
could be used to control soils under difficult
Very wet soils need draining and textiles were
used to line drains, to prevent mud and silt from clogging up the drains. small access roads constructed over very soft wet soils. [1].
Similarly, engineers tried to use textiles beneath
It was found that these textiles helped to
increase the life and performance of roads. laying of textiles on the coast to prevent erosion by wave action. use of geotextiles spread geographically worldwide and in area terms their use increased almost exponentially. increase into the 21st century [1].
Also, early work was being undertaken in the
During the last 20 years of the 20th century, the
It is expected that their use will continue to
Geosynthetics
In the field of civil engineering, membranes
used in contact with, or within the soil, are known generically as Geosynthetics.
This term encompasses permeable textiles,
plastic grids, continuous fibres, staple fibres and impermeable membranes.
Textiles were the first products in the field,
extending gradually to include additional products, but have remained by far the most important of the range.
Geotextile types
Geotextiles basically fall into five categories:
Woven
Heat-bonded nonwoven
Needlepunched nonwoven
Knitted and
Fiber/soil mixing [1]
The most common types of geotextiles are woven and non woven.
Woven for: Sediment control Unpaved road bases Strengthening paved roads Erosion protection subsurface drainage.
It possesses the following features: Woven Polypropylene UV Resistant Rot Resistant Biological Degradation Resistant Chemically Inert
http://www.erosionpollution.com/geotextiletypes.html
Non woven geotextile
Used for
Roads
Roofs
Railroads
Ponds
Dams, trenches
Landfills.
Possess the following features: 100% Propylene Staple Fibers Needle-Punched Random Network Formation UV Resistant Rot Resistant Biological Degradation Resistant Stable Within 2-13 pH
http://www.ecvv.com/product/ 2625680.html
http://www.erosionpollution.com/ geotextile-types.html
The main geotextile fiber-forming polymers
Two most common fiber polymers used for
the manufacture of geotextiles are:
polypropylene and polyethylene
Polyester is almost inevitably used when high
strengths are required
Essential properties of geotextiles
Three main properties which are required:
Mechanical responses
Filtration ability
Chemical resistance
Mechanical responses
It includes:
The ability of a textile to perform work in a
stressed environment environment
Ability to resist damage in an arduous
Ability to cope with the expected imposed
stresses and its ability to absorb those stresses over the proposed lifetime of the structure without straining more than a predetermined amount
Mechanical tests [1]
tensile testing by means of a wide strip test pore size testing by dry sieving water flow testing normal to the plane of the textile puncture resistance testing creep testing perforation susceptibility (cone) testing water flow testing in the plane of the textile testing of sand/geotextile frictional behaviour
Geotextile and filtration
The woven geotextiles separation action
prevents the mixing of dissimilar soils allowing each soil layer in the road structure to function as intended. properties of woven geotextiles impart stability into the road section reducing rutting and extending roadway life.
The high tensile strength and low elongation
[http://www.nilex.com/products/geotextiles/woven_geotextiles]
Chemical resistance
There are four main agents of deterioration:
Organic
Inorganic
Light exposure
Time change within the textile fibers [1].
References
[1] Rankilor, P.R., Textiles in civil engineering,
in Handbook of Technical Textiles A.R. Horrocks, Anand, S. C., Editor 2000, Woodhead Publishing Ltd Cambridge.
