GEOSYNTHETICS IN
ROAD CONSTRUCTION
S.Jaswant Kumar
Chief General Manager (Planning and Quality)
National Highways Authority Of India
Introduction
Geosynthetic-Overview
Geosynthetics Applications
Impediments
Suggestions
Geosynthetics
 Modern
civil engineering construction
materials
 Modify/Improve soil/geologic material
behaviour
 Developed/Synthesized for specific
function or application in construction
 More than 1billion sq m annual use
Geosynthetics –The wide variety
 Geotextiles
–Woven, non-woven Filter
fabrics
 Geogrids
 Geomembranes
 Geocomposites
 Geonets, Geofibres,mesh mattings,
Geopipes, Geotubes.
Woven or Knitted Geotextiles
Non-woven Geotextile
Uniaxial Geogrid
BIAXIAL GEO GRID
Woven or Welded Geogrids
Geonets
Geocomposites
Geosynthetics – composition
 Polypropylene
H
DPE
 Polyester
 PVC
 Synthetic Rubber
 Natural fibres – Jute, coir
COIR GEOTEXTILES
Geosynthetics – the functions
 Separation
 Drainage
 Filtration
 Reinforcement
 Moisture
 Cushion
barrier
Separation function
Drainage function
Filtration function
Reinforcement function
REINFORCEMENT FUNCTION
Geomembrane Seepage Barrier
Lateral Restraint
Bearing Capacity Increase
Membrane Tension Support
GEOCELL MATRESS UNDER
EMBANKMENT ON SOFT SOIL
Geocell in the making
Geotextile wrapping of Geocell
Concrete Facia Panels for GRS
Wall
Erosion Control Blanket
Design Requirements for
Asphalt Pavements
Grid Locations for Asphalt
reinforcement
Reflection Cracking

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Locate near to
existing discontinuity
Mechanistic design
method still evolving
Stiff geogrid best
Geotextile can
waterproof
Rutting in Overlays

Locate where
strains are largest;
mid-depth
 Increase in life to
critical rut of three
times
 Requires stiff
geogrid
GLASS GRID UNDER OVER LAY
ROAD WIDENING
Overlay
GLASS GRID
bitumen emulsion layer
ROAD WIDENING
Other Applications in Highways
 Geosynthetic
Reinforced Soil Walls
 Reinforced soil slopes
 Subsurface Drainage systems-trench
drains, strip drains
 Stabilising canal road systems in
expansive soil regions.
 PVD.
Geosynthetic Reinforced Soil
Wall
Geosynthetic Band drains
Impediments
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Most of the Geosynthetics are imported.
Test Methodology they adopt is from country of
origin.
Test could be of:International standards (ISO TC221 Geosynthetics).
European Standards (CFN TC Geosynthetics).
German Standards DIN textiles norms.
British Standards BS
American Standards ASTM.
Very few Indian Standards.
specifications
 Specifications
are from international
organizations.
 AASHO.
 British Textile Technology Group - BTTG.
 DGGT- EBGEO, Germany.
 Geosynthetics Research Institute, USA
Presence of large number of test methods &
specifications are a matter of concern and
confusion.
Need for Testing
 Index
Testing-Basic Properties of Products
 Quality control tests- Rapid testing to
assure continuity of equality.
 Performance testing- Testing of
Geosynthetics in contact with soil under
standard conditions in the lab to provide
better simulation of site conditions. Also in
full scale on site.
R&D FACILITIES
 Available
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R&D facilities:-
IITs, Delhi, Chennai, Mumbai.
BTRA
CRRI
CCRI, Coir Board
SASMIRA
Manufacturers Lab.
R&D FACILITIES
The existing Labs may have excellent facilities
but
 May not necessarily have all relevant
facilities for test house.
 May not maintain ambient temperature and
humidity as required by ISO (21± 2°C &65%).
 May not have necessary Grips for all varieties
of Geosynthetics.
 May not have skilled/Trained Technicians.
 Not accredited.
SUGGESTIONS

Need for establishing national organisation to
address the problems.
Role:1)
Functions as a Geosynthetics test house.
i.
QC checking at the place of manufacturer.
ii.
Property assessment of the product for the
designer.
iii.
3rd party quality control testing of product.
iv.
Testing & evaluation for product certifications.
v.
Testing for R&D needs.
SUGGESTIONS
2)
3)
4)


Render advice to the industry & Govt.
Organise short refresher & training
programs.
Develop laison with all specifying dept.
like BIS, IRC & International institutions.
Immediate Standardization of
specifications, test procedures.
Code on the lines of BS 8006.
THANK YOU