Geotextiles in pavement
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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.
Geotextiles in pavement
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- 2. Introduction Types of geotextiles Placing of geotextiles in pavement Functions and applications of geotextiles in pavement References 2
- 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. 3
- 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 4
- 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. 5
- 6. Fig1. woven type geotextile 6
- 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 7
- 8. 4. combination bonding Thicker than woven type geotextiles. These are flat porous sheets. Fig.-non-woven geotextile 8
- 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 9
- 10. Between aggregate layer and natural subgrade layer. Mechanically or with hand. It will be rolled around a pipe, just unroll it. 10
- 11. Fig.3 placing of geotextile mechanically 11
- 13. These are the main functions performed by geotextile in pavement- 1. Separation 2. Filtration 3. Reinforcement 4. Drainage 5. Erosion control 13
- 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. 14
- 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. 15
- 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. 17
- 18. Fig.-geotextile as filtration layer 18
- 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. 19
- 20. Requirement- Geotextile should posses enough strength. Knitted type of geotextile is preferred. Fig.-geotextile performing like reinforcement in pavement 20
- 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. 21
- 22. The geotextile protects soil surfaces from the tractive forces of moving water or wind and rainfall erosion. 22
- 24. Geotextiles are very important part of pavement construction regarding its strength, durability, and working performance. Very useful in case of silt and clay. 24
- 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 25
- 27. THANK YOU 27