STANDARDS ON GEOSYNTHETICS M.S.Verma Vice President – Technical Textiles M/s Reliance Industries Limited
GEOSYNTHETICS – GLOBAL OVERVIEW• Worldwide demand for geosynthetics is projected to rise 5.3 percent annually to 4.7 billion square meters in 2013.• China, India, Russia and other countries with large-scale infrastructure developments planned, and evolving environmental protection regulations and building construction codes are expected to register the strongest advances.• Geo-synthetics are especially useful in an environment of increasing land scarcity, increased awareness of seismic hazards, and need more stringent environmental regulations especially in the context of India.• Strong growth in China is demonstrated by use of geosynthetics in almost all government sponsored/controlled projects in various areas while such is not the case in India.
GEOSYNTHETICS – GLOBAL OVERVIEWGlobal Scenario 10% 5% 1%• USA dominates the consumption 14%• China Fast Catching up 51%• India consumes less than 1.5% 19% Geosynthetics, produced globally USA China• Tremendous Potential Exists in India Europe Other Asian Countries Australia India• Global Manufacturers like Terram, Du- pont, Naue focussing on Indian Market India consumption ~ 1.5 % at 9 KTA Awareness Creation – First Step Towards Enhanced Consumption
INDIAN ROAD NETWORKQuality road …..means huge potential for Geo textile
INFRASTRUCTURE DEVELOPMENTInfrastructure Scenario• Total Investment to double in 2011-12 vis-à-vis 2007-08, Projected to cross 500,000Cr• 2009-10 Govt. to spend Rs. 60000Cr only for up-gradation of Roads• Private Sector Investment in Roads to cross 35% by 2011-12• The Eleventh Five Year Plan has a special focus on Rural Infrastructure Development Opportunities for Geosynthetics
GEOSYNTHETICS – REGULATION NEED IN INDIA• In view of large potential for cost savings, environmental protection, safety, economic and social importance of geo-synthetics in the infrastructural development in India and the environmental protection by their use, it is essential that their use is made mandatory in India just like mandatory regulation of fly ash or iodized salt, specially in the following areas: – All highways, expressways and coastal roads, reinforcement with geosynthetics must be mandatory when the CBR ratio is ≤ 3.5. – In rural road construction as these are repaired / reconstructed after a prolonged period. – All coastal roads embankments which are on soft soil foundation, use of geosynthetics must be mandatory.• The BOT system, needs be modified to DBOT to give emphasis on the initial design of the project and the latest technology like geosynthetics.
What are Geo-synthetics ?• Geo-synthetics are synthetic products, where at least one of the components is made from a synthetic or natural polymer, in the form of a sheet, a strip or a three dimensional structure, non-woven, knitted, or woven which is used in contact with soil/rock and/or other materials in geotechnical and civil engineering applications .• These include: – Planar structures (geomembranes, geotextiles, geosynthetic barriers, geonets, geogrids, geostrips, geospacers and geomats, etc.) and – Three-dimensional structures (geocells, geofoams, gabions and concrete filled mattresses).
POLYMERS USED IN GEOSYNTHETICSChemically linked large molecules of carbon atoms with hydrogen or other atoms attached Polypropylene Polyethylene Polyester Polyamide Polystyrene Poly Vinyl Chloride PP/Polyester /PE Geosynthetics – Most widely used across the Globe (more than 95 percent)
GEOSYNTHETICS AREAS OF Application• In Roads and Pavements: – Subgrade separation and Stabilization, – Base Reinforcement, – Overlay Stress Absorption and Reinforcement.• In Subsurface Drainage: – Subgrade dewatering, – Road base drainage, – Structure drainage.• In Erosion and Sediment Control – Hard Armor Systems, Silt Fence.• In Reinforced Soil Systems: – Embankments over soft foundations, – Reinforced Steepened slopes, – Reinforced soil walls.• In Seepage control systems – Structure water proofing, – Environmental Protection.• In Support Systems: – Prefabricated Systems and On-site Fabrication
Advantages of Geo-synthetics• Cheaper in poduct cost, transport and installation.• Can be designed (predictability)• Can be installed quickly with flexibility to construct during short period.• Consistent over a wide range of soils• Space Savings• Material Quality Control - More homogeneous than soil and aggregates.• Better Construction Quality Control at site• Easy Material Deployment• Less Environmentally Sensitive• Improved performance and extended life• Increased safety factor• Compatible with field conditions• Increased service life of flexible pavement section by a factor of 2.5 to 3.0 for weak subgrades (CBR 2%) and by 2.0 to 3.3 for moderate subgrades (CBR 4.2 to 4.5%)• Increase in allowable load bearing capacity by 40 to 50% for subgrade CBR>3 and well over 50% for subgrade CBR<3
Economic Importance of Geosynthetics• Commonly accepted as durable, long lasting and environmentally safe solutions to geotechnical engineering projects.• The cost of geo-synthetics applied usually between 3 to 5 per cent of the total cost of projects.• For a number of projects, savings of 30 per cent in total project costs have been reported.• Minimizes the regular repair and maintenance costs directly.• Prevent accidents, increase efficiency of structures, minimize pollution and leads to efficient use of natural resources.
Environmental Importance of Geosynthetics• The civil engineering structures need to have long term durability to prevent potential ecological disasters (floods, draughts, earthquakes, global warming) . Geosynthetics provide such long lasting solutions with minimum cost.• Geo-techs are difficult or impossible to degrade. However, in view of their inert nature they can be disposed off without the danger of contamination.• Geosynthetics assist the environment by acting as a containing barrier for toxic materials.• The envisaged functional lifetime of geosynthetics is extremely long, in many cases over 100 years.• Geosynthetics provide sealing and capping of pollution due to chemicals released after road and rail accidents into groundwater areas.
Geosynthetics -National / International Regulation• Worldwide, approx. 40 countries have legislation/regulations (GRI Report).• In Europe, the Construction Products Directive (89/106/EEC ; M/107) has to be followed and the use of geo-textiles is mandatory.• In Japan, the Government Directive applies to landfill construction sites.• In the US, many Govt agencies (fedral and state) have mandated the use of geo-synthetics in many applications. e.g. the use of silt fence fabrics for erosion and sediment control. US Environmental Protection Agency has mandated use of geo-synthetics in landfills (under Resource Conservation and Recovery Act). Also, in many applications geo-textiles are specified by govt agencies as the best product.• Similarly California State has mandated the use of asphalt overlay over existing roadway.• It is essential that their use is made mandatory in India in order to have increased efficiency with potential large cost saving, safety of structures and minimum environmental pollution including large saving of natural resources .
MAIN ROADBLOCKS FOR INCREASING USAGES OF GEOSYNTHETICS IN INDIA• Lack of desired legislation• Lack of required standards on geosynthetic products as well as on design, construction and installation guidelines• Lack of policy / regulatory initiatives by the central and state governments• Lack of awareness of standards and guidelines by the site engineers / field staff• Lack of national certifying and accreditation agencies for geosynthetics in the country• Lack of R&D facilities• Incompleteness of existing standards and guidelines
Geo-synthetics Standards• ASTM Standards• ISO standards (ISO/TC221)• Indian standards (BIS)• AASHTO standards• FHWA standards• NORDIC guidelines• British Standards• International Geosynthetic Society standards (IGS)• Geosynthetic Research Institute (GRI)• Geosynthetic Materials Association (GMA)• US Provinvcial standards• Industrial Fabrics Association International (IFAI)• Geo-synthetica• International Erosion Control Association (IECA)• European Center For Standardization (CEN)
AIMS OF STANDARDS• Interchangeability• Variety Control• Fitness for Purpose• Compatibility• Safety• MAXIMUM OVERALL ECONOMY IN TERMS OF: – COST – HUMAN EFFORT – CONSERVATION OF RESOURCES RESULT: – POSSIBLE SOLUTION TO RECURRING PROBLEMS – DEFINITION OF THE QUALITY LEVEL OF PRODUCTS
TECHNICAL COMMITTEE STRUCTURE (Members From) Manufacturer Manufacturer s s BASIC APPROACH Consensus Principle Consumers, Government Consumers, Government Balanced Committee Departments Departments StructureTechnologists , Regulating Technologists , RegulatingAuthorities, Testing Authorities, TestingLaboratories, Consultants, Laboratories, Consultants,Universities, Other Experts Universities, Other Experts
BIS/IRC/RDSO STANDARDS ON GEOSYNTHETICS• BIS standards mainly on test methods, jute & coir geotextiles, PVC / HDPE geomembrane for waterproof lining (IS 14715:2000; IS 14986:2001; IS 15869:2008; IS 15871:2009;IS 15909:2010; and IS 15910:2010 Geosynthetics for highways)• IRC standards mainly on recommended practices/guidelines and are being revised to include geosynthetics• IRC/RDSO standards generally do not refer BIS standards and requirements of geosyntheics in both are at large variation.• Geosynthetic specifications mentioned in IRC/RDSO standards are generally incomplete.• BIS standards are also incomplete w.r.t. guidelines for design, construction, installation and storage which are essential to get the best results of geosynthetic applications.• There appears no proper coordination between IRC and BIS• Standards activity in IRC/RDSO is not universally acceptable and needs drastic changes to include all stakeholders
EUROPEAN AND INTERNATIONAL GEOTEXTILE STANDARDS - FUNCTIONS AND APPLICATION
EUROPEAN AND INTERNATIONAL GEOTEXTILE STANDARDS
REQUIREMENTS OF GEOSYNTHETICS• General Properties Index Properties – Material Type & Construction Strip tensile strength (2% & 5% strain and ultimate tensile strength) – Polymer(s) Grab strength – Mass Creep resistance – Thickness Flexural strength – Roll dimensions Cutting - Trapezoidal tear strength – Specific Gravity Shear modulus – Absorption Poisson’s ratio Burst Strength Puncture Resistance Penetration Flexibility (Flexural Strength) »
REQUIREMENTS OF GEOSYNTHETICSEndurance Properties Hydraulic Properties– Abrasion Resistance Apparent Opening Size (AOS),– UV Stability Percent Open Area, Porosity– Biological Resistance Permeability / Permittivity– Chemical Resistance Soil Retention Ability– Wet/Dry Stability Clogging Resistance– Temperature Stability In-Plane Flow Capacity– Long term durabilityPerformance – Soil / Fabric Properties– Stress - Strain– Creep– Friction/Adhesion– Dynamic and Cycling Loading– Soil Retention– Filtration
Parameters for Geo-synthetic Selection• Geosynthetic Specification should also cover: – Material Selection – Designing of Geosynthetic – Functional Requirements – Application and Performance Requirements – Durability Requirements – Survivability Requirements – Required Geosynthetic Structural and Integrity Properties – Storage, handling and installation requirements