A PRESENTATION ON APPLICATIONOF NATURAL FIBRE IN GEOTEXTILESPRESENTED BYSATYARANJAN BAIRAGIDEPARTMENT OF JUTE AND FIBRE TECHNOLOGY(INSTITUTE OF JUTE TECHNOLOGY)UNIVERSITY OF CALCUTTA
Natural fibres are extracted from plants and are then convertedinto yarns by spinning. These fabrics are sometimes treated withrot resistant materials or reinforced with synthetic fibres toenhance their durability under different soil conditions withoutaffecting its strength and other properties. Fabrics from naturalfibres such as jute, flax, coconut , coir etc. are used to improvesoil erosion control and drainage applications.INTRODUCTION
• What is Geotextile ?The ASAE (Society for Engineering in Agricultural, Food, andBiological Systems) defines a geotextile as a "fabric orsynthetic material placed between the soil and a pipe, gabion,or retaining wall: to enhance water movement and retard soilmovement, and as a blanket to add reinforcement andseparation." A geotextile should consist of a stable networkthat retains its relative structure during handling, placement,and long-term service. Other terms that are used by theindustry for similar materials and applications are geotextilecloth, agricultural fabric, and geosynthetic.• What are Geosynthetics ?American Society for Testing and Material (ASTM) defines geo-synthetics as a planner product manufactured from polymericmaterial used with soil, rock earth or other geo-technicalengineering related material as an integral part of a man-madeproject, structure or system.
GENERAL ATTRIBUTES OF MATERIALS High moisture absorbing capacity Excellent drapability (the best of all GTs) High initial tensile strength Low extension at break High roughness co-efficient High spinnability Bio-degradable; soil nourisher Renewable resource, easily available Economical Eco-friendly
TESTING PROPERTIES OF MATERIALSREFERENCE :• Jute Manufacturers Development Council
FUNCTIONS OF FIBRES IN GEOTEXTILES SEPARATION FILTRATION DRAINGE REINFORCEMENT CIVIL ENGINEERING APPLICATION1. ROAD CONSTRUCTIONS2.PROTECTION OF RIVER BANKS3.EMBANKMENTS4.PREVENTION OF RAILWAY TRACK5.CONSOLIDATION OF SOFT SOIL
SEPARATION Segregates two layers, preventing intermixing Facilitator to natural consolidation of soil
FILTRATION Two contrasting functions – soil retention allowing pore-water through and along the fabric Provides a permanent mechanical andhydraulic filter stability
DRAINAGE Acts as a drain within its own thickness. Permittivity and Transmittivity of JGT are high
REINFORCEMENT Acts against rotational slides, lateral dispersion and vertical subsidence Exerts confining action on soil Partially absorbs effective stress,preventing shear failure.
CONCLUSIONThese natural fibre geotextiles are found to have superiorproperties in comparison to the mid-range of synthetic geotextilesfor soil reinforcement, separation, filtration, drainage and civilengineering etc. When considering strength and frictionalresistance. The high degree of frictional resistance of thevegetable fibre geotextiles is probably developed from both thecoarseness of the natural fibre yarns. These vegetable fibregeotextiles will be much more environment-friendly than theirsynthetic counterparts and the fibre themselves are a renewableresource that is biodegradable