This document discusses the types and uses of geotextiles in pavement construction. It describes the three main types of geotextiles - woven, non-woven, and knitted - and explains how they are manufactured. The key functions of geotextiles in pavement are identified as separation, filtration, reinforcement, drainage, and erosion control. Geotextiles are typically placed between the subgrade and aggregate base layers in pavement to prevent mixing of materials and increase pavement strength and lifespan.
2. Introduction
Types of geotextiles
Placing of geotextiles in pavement
Functions and applications of geotextiles in
pavement
References
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3. Geotextiles are polymer fabrics used in the
construction of roads, drains, harbour works,
breakwaters, and for land reclamation and many
other civil engineering purposes.
Used with geotech. eng. related materials as an
integral part of human made structures.
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4. Geotextiles are usually made from polymers such as
polyester or polypropylene.
Further prepared in 3 different categories-
1.Woven type
2.Non-woven type
3.Knitted type
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5. These were the first to be developed from the
synthetic fibers.
Manufactured with a process of weaving narrow strip
of film together to form one large piece. Weaving is
done by interlocking perpendicular threads.
Can be used in roadways as it has higher load
capacity.
Does not have good drainage characteristics.
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7. Can be made from either continuous filament
or staple fibres, these are continuously
extruded and spun, placed on a moving belt, to
form mat, which is then bonded by using any
of these processes-
1. needle-punching
2. heat bonding
3. resin bonding
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8. 4. combination bonding
Thicker than woven type geotextiles.
These are flat porous sheets.
Fig.-non-woven geotextile
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9. Manufacturing process adopted from clothing
textiles industry, and that process is called knitting.
Interlocking a series of yarns together is made in this
process.
Fig.-knitted type geotextile
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10. Between aggregate layer and natural subgrade
layer.
Mechanically or with hand.
It will be rolled around a pipe, just unroll it.
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13. These are the main functions performed by
geotextile in pavement-
1. Separation
2. Filtration
3. Reinforcement
4. Drainage
5. Erosion control
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14. These are main layer in a section of pavement-
1.Subbase/Subgrade layer
2.Base/Aggregate layer
3.Surface layer
Geotextile is placed between subgrade and base
layer-as a separater, so that they can perform
effectively.
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15. Prevent the mixing of two dissimilar materials.
Greater density of provided material can be
achieved.
Releases pore water pressure, that results in
consolidation of subgrade.
Life of pavement increases.
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17. Oldest and most widely known function.
The geotextile is placed in contact with and
down gradient of soil to be drained.
Allows water to pass and retains soil particals.
Permeability and long time clogging are the
properties of geotextiles, which are considered
in this function.
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19. Geotextile as reinforcement means a
significance increase in pavement-strength.
Mechanism-It is the lateral restrain through
friction between soil and geotextile.
Geotextile resist the tensile force developed.
Geo-grids are in common use in US instead of
Geotextiles.
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20. Requirement-
Geotextile should posses enough strength.
Knitted type of geotextile is preferred.
Fig.-geotextile performing like reinforcement in pavement
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21. Geotextile acts as conduit for the movement of liquid
in the plane of geotextiles.
Thick non-woven type geotextiles are commonly
used for this function.
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22. The geotextile protects soil surfaces from the
tractive forces of moving water or wind and
rainfall erosion.
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24. Geotextiles are very important part of pavement
construction regarding its strength, durability, and
working performance.
Very useful in case of silt and clay.
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25. 1. Sharma, Kanaungo, Khatri.,2014, “Application of
Geotextiles in Pavement Drainage Systems,
International Journal of Civil Engineering
Research.volume” 5(4),385-390
2. Chair, Flintsch, Trani., “Effectivness of using
geotextitles in flexible pavements: life-cycle cost
analysis” Feb 27, 2006.
3. Guyer, Pe, Ra. 2009, “An introduction to
geotextile in pavement and drainage application”,
C02-019
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