download complete seminar from the link given
Geosynthetics is a “generic term” applied to cover several products such as geotextiles, geomembranes, and geocomposites etc., which have different roles to play in dealing with problematic soils, though they may be manufactured from the same raw material. Coir and jute are examples of natural geo-textiles. Coir is a versatile hard fibre obtained from the husks of coconut.. Coir is a renewable natural material available abundantly in India and produced at low cost. This seminar deals with the usage of coir for applications like, erosion control, reinforcement and stabilization of soil and is preferred to any other natural fibres Coir is a sufficiently eco-friendly product and so its application will never sustain any damages to environment. Consolidation of soil, especially of soft clayey structure is being recognized as a problem that requires effective and economical solution. Coir is one of the materials used as horizontal blanket over vertical drains. It is as such an economical answer to the problems related to primary consolidation of soft clay. This seminar also deals with the application of “horizontal coir blankets over vertical drains” method in the construction of an embankment in NH-17, near Kozhikode, Kerala, India. Also the method used for the protection to the side slopes of Kabini Canal is discussed.
GEOSYNTHETICS is a "generic term" applied to cover several products such as geotextiles, geomembranes, geocomposites, geogrids etc. The geosynthetics can be called upon to perform one or more of the following functions:
(i) Separator to keep apart two types of soils or materials.
(iii) Erosion control and interface protection.
(iv) Tensioned membrane to impart strength to weak foundation soil.
The most commonly used synthetic fibers in the manufacture of geosynthetics are: polypropylene, polyester, polyethylene, and poly-amide (nylon). Natural fibers like coir, jutes etc., are also used as geotextiles.
Coir is a biodegradable organic fibre and hardest among other natural fibres.The fibrous material forming part of the soft mass surrounding coconut, the fruit of the tree “Cocos Nucifera” or the coconut palm is world over known as coir. Coconut husk is the raw material for the coir industry, which is available in enormous quantities wherever there is large-scale coconut cultivation.The Coir fibre is one of the hardest natural fibres because of its high content of lignin. Coir is much more advantageous in different application for erosion control,reinforcement and stabilization of soil and is preferred to any other natural fibres. The fibre is hygroscopic, with moisture content of 10% to 12% at 65% relative humidity and 22% to 55% at 95% relative humidity Of all the natural fibers, coir possess the greatest tearing strength, retained as such even in very wet conditions The physical appearance and quality of the fibres vary widely. The colour of the fibre is not only influenced by the species of the coconut from which it is derived but also its maturity, time lapse between dehusking and retting etc. However under identical conditions of these variables, the fibres extracted from infant nuts exhibit a pale yellow color. The intensity of color and thickness increase with age and the fibres are remarkably stiff and posses good extensibility. Morphologically, coir is a multi cellular fibre with 12 to 24 microns in diameter and the ratio of length to thickness is observed to be 35. Cells of the fibre surface are occasionally covered with the silicised stigmata. The chemical constituents have found to be cellulose, lignin, hemi cellulose and pectin. The percentage of the ingredients in the fibre is largely governed by the age of the coconut from which it is derived. Cellulose and lignin are the major constituents and higher lignin content makes the fibre stiffer and tougher.