Quality creates value 1 Emerging Technologies For Geotextiles(Geosynthetics)
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Transcript of Quality creates value 1 Emerging Technologies For Geotextiles(Geosynthetics)
Quality creates value
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Emerging Technologies For Geotextiles(Geosynthetics)
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Technical Textiles
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Global market scenario for geosynthetics
Global market has grown to US$ 3000 Million in 2009 Global growth of geosyntethics is estimated by 5% Geosyntethics account for 0,8% of the total technical
textile segment
India Geotextiles market is approx. RS. 226 crores Rs. 105 crores imported production RS. 121 crores domestic production expected growth is 12%, on long term up to 20%
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Geosynthetics
Geosynthetics is a generic term that is used to describe a product with at least one component manufactured of synthetic or natural polymer ,for use with soil, rock or other materials used in public works projects.
Types of geosynthetics Geogrid Geotextile Geocomposite
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Geosynthetics - Functions
Reinforcement-Improving mechanical properties of soil
Separation-Long term functionality of all structural layers is provided by the use of geosynthetic material between two dissimilar geotechnical materials to prevent mixing.
(Such requirement is there for roads & railways)
Erosion control-To prevent the surface erosion of soil particles because of water/wind forces.
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Geosynthetics - Applications
Reinforcement -
Basal Reinforcement/Ground stabilisation--Use of geosynthetic material for improvement of load bearing capacity.Geosynhetic materials are utilised to balance eneven settling,absorb loading forces & reduce the thickness of expensive coarse grained material.
Supporting structures -Retaining walls & Bridge Abutments –While constructing supporting structures or steep embankments of soil, shear strength of which would be exceeded in normal circumstances. It is possible to achieve the required safety using horizontal reinforcement of embankment layers with geosynthetic material(geogrid or geotextile)
The face wall can be made of Concrete elements ( prefabricated blocks, panels).
It can also be made as a Soft Face ( by wrapped-around method).
Asphalt reinforcement-Asphalt layers have low strength,Glassgrids or geocomposites are used to increase the strength of the asphalt layer & ensure its uniform distribution in larger areas.
They prevent formation & sprading of reflex cracks by absorption of shear forces.
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Geogrid
GEOGRIDS are geosynthetics formed by a regular network of integrally connected elements with apertures greater than 10mm to 100mm to allow interlocking with surrounding soil, rock, earth and other surrounding materials to function primarily as reinforcement
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Geogrids: woven grids for the use in roads, dams, railways…
A wide spectrum of manmade fibers and natural fibers
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Geogrids - Functions
1. Soil reinforcement
They are used primarily for soil reinforcement. Their strength can be greater than the more common geotextiles. Geogrids have a low strain and stretch only about 2 to 5% under load.
The most important characteristics of geogrids are high water drainage combined with exceptional mechanical strength and long term creep resistance.
2. Soil stabilization
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Geogrids - Applications
Soil reinforcements in embankments and walls
Subgrade stabilization
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Uniaxial Geogrids - Applications
segmental block retaining walls, slope reinforcement, pile cap platforms and base reinforcement applications such as roads, car parks and rail line construction.
Biaxial Geogrids - ApplicationsEquipped with dual directional strength combined with the interlocking system, Merex BL products are specially designed for foundation applications.
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Biaxial Geogrid – Sub-grade Stabilisation
Geogrids - Applications
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Biaxial Geogrid – Ground Improvement for Tank Foundation
Geogrids - Applications
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Geogrids are open mesh but also closed constructions
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Biaxial Geogrid – Installation of Geogrid at balast level
Geogrids - Applications
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Glassgrid-A type of Geogrid
The GlassGrid® Pavement Reinforcement System provides additional support to resist the migration of reflective cracks in pavement structures.
Cracks migrate toward surface in unreinforced overlay.
Cracks are redirected in GlassGrid reinforced overlay.
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Glassgrid
Glassgrid is an exceptionally strong reinforcing material specially developed for pavements.
It consists of glass fibre strands arranged in a grid structure and covered with a polymer coating and a pressure sensitive adhesive.
Each strand has a remarkably high tensile strength and high modulus of elasticity at low elongation.
This combination of outstanding tensile strength and high modulus makes Glasgrid actually stronger than steel.
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Geotextile
Geotextiles form one of the two largest group of Geosynthetics.
They are textiles in the traditional sense, but consist of natural fibers like jute, coir or synthetic fibers depending on the requirement, mainly whether biodegradation is desired or not.
These are fabric or cloth-like materials that are classified based on the method used to manufacture the fabric: either woven or non-woven.
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Geotextile - types
Woven monofilament
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Geotextile - types
Woven multifilament
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Geotextile - types
Woven Slit film
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Geotextile
Woven Geotextile:
Woven construction produces geotextiles with high strengths and moduli in the warp and fill directions and low elongations at rupture.
Woven construction produces geotextiles with a simple pore structure and narrow range of pore sizes or openings between fibers.
Woven geotextiles are commonly plain woven, but are sometimes made by twill weave or leno weave (a very open type of weave).
Woven geotextiles can be composed of monofilaments or multifilament
yarns made up of PE,PVA,PP or natural textile material.
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Geotextiles: Mass per unit area - Fabric in comparison with nonwovens
Te
ns
ile
str
en
gth
kN
/m
Mass per unit area g/m²
up to 5x higher
Source: material report Hochschule Rapperswil
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Geotextiles: Elongation - Fabric in comparison with nonwovens
Mass per unit area
of 200 g/m²
Fabric
Thermally bonded nonwoven PP
Needle punched nonwoven PES
Needle punched nonwoven PP
Elongation %
Te
ns
ile
str
en
gth
kN
/m
Source: material report Hochschule Rapperswil
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Geotextile - Applications
Separation
Reinforcement
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Geotubes -Main Applications
Dewatering solutions
Geotubes used in artificial Island projects
Shoreline (Coastal) protection
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Geotubes
Dewatering
Solution
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DORNIER weaving machines can contribute to an efficient production of
various types of geosynthetics.
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Geogrids in closed and open constructions ...
... used for geotextile and agriculture purposes
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..offers stress- free insertion for all kinds of yarns
Online coating procedure on DORNIER rapier machines
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Positive weft yarn handling through the entire weft insertion
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No guiding elements in the shed
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Open shed insertion system
DORNIER unique open shed insertion guarantees equal weft tension over the full fabric width, minimum friction between warp and weft
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Main parameters for Geogrids
materialtensile strength
mesh size
PP, PES, Glass, Jute, …
40 – 400 kN/m and more
10x10 mm19x28 mm31x31 mm
…
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Example for Geogrid-Specification
material
tensile strength
mesh size
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Example for Geogrid-Construction
Mesh size20 x 20 mm
Web size in warp direction
Web size in weft direction
x mm
x mm
Web size is not fixed in
specification!
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Example for Geogrid-Calculation1. Requested tensile strength of e.g. 109 kN/m2. Requested textile type PET (Polyester high tenacity)3. Search for fiber type with high tensile strength e.g. 82.5 cN/tex 4. Search for standard yarn-types with parameters e.g. 1100 dtex 2200 dtex5. Evaluation of the yarn tensile strength e.g. 0.088 kN 0.176 kN6. Evaluation of number of threads e.g 1239 6197. Addition of 10% more threads for loss in production 1362 6818. Requested mesh size of e.g. 20 x 20 mm9. Preestimated width of the web size 9 mm 6 mm10. Evaluation of number of meshes per meter here e.g. 34 3811. Evaluation of number of threads per mesh here e.g. 27 1412. Evaluation of the yarn-diameter here e.g. 0.337 mm 0.477 mm13. Exspected Web-size in warp-direction here e.g. 9.1 mm 6.7 mm14. With different patterns the web size can be influenced
End of the first run!Second run! Pos. 9 - 13
Adjustment of the proportion of mesh-size and web-size.
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Geogrid-Construction
Mesh size20 x 20 mm
Web size in warp direction
Web size in weft direction
7 mm
6 mm
Tolerance inmesh size +/- 3 mm
14 weft threads in double weft insertion
(7 picks)
14 warp threads
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Geogrid made with Leno
face side reverse side
leno thread
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Online coating procedure on DORNIER rapier machines
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Coating-material as online coating is required in most cases
PVC Bitumen Latex Plastisol Silicon
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Glass fabric woven on DORNIER rapier or airjet machines
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Reinforcements for facades – Glass roving 68 to 600 tex
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Today and furture markets / building industry
Reinforcement of concrete support structures with carbon grid fabrics and UD structures
reinforcement and repair of concrete components
silos / tanksbridges / highway lanes
tunnels / tubes
Delicate structures and elements of facades
Vibration damping
Explosion protection / earthquake protection
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Composition of glass yarn fabrics ...
... used as wall paper - fireresistand
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Producers:
Hüsker (D)
Propex (D)
Synteen/Lückenhaus (D)
Edilfloor (I)
Low & Bonar (GB) (MehlerTexnologies gehört L&B)
TenCate (NL)
Kordarna (CZ)
Stradom (PL)
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DORNIER weaving machines are the most reliable instruments having the widest potential for the
production of technical fabrics
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