500 likes | 760 Views
BITUMEN. PAVES THE WAY. BITUMEN. A BRIEF HISTORY. Bitumen - HISTORY. Used in Building and Paving since Ancient times. Oldest adhesive known to man. Used in 3500 B.C. as mortar for building stones and paving blocks in Mesopotamia.
E N D
BITUMEN PAVES THE WAY
BITUMEN A BRIEF HISTORY
Bitumen - HISTORY • Used in Building and Paving since Ancient times. • Oldest adhesive known to man. • Used in 3500 B.C. as mortar for building stones and paving blocks in Mesopotamia. • Used for water tightening of reservoirs, canals, bathing pools & embankments of rivers in Indus Valley. • Used for Mummification in 300 B.C. • Rock Asphalt used for flooring/sidewalks in France in 1800 A.D. • First road surfacing with Bitumen done in New Jersey in 1870 A.D. • From 1900 onwards Bitumen produced from Refineries being used extensively.
BITUMEN THE PRODUCT
Types of Binders • TAR • NATURAL ASPHALT / ROCK ASPHALT / LAKE ASPHALT • BITUMEN
Tar • COKE OVEN TAR • Produced at temperatures above 1200OC during manufacturing of coke. • High aromatic content. • Pitch content - 50 %. • LOW AROMATIC TAR • Produced at temperatures 600OC to 700OC. • Less viscous. • Paraffinic in nature. • Pitch content - 35 %.
Natural Asphalt / Rock Asphalt / Lake Asphalt • Naturally occurring Bituminous binder. • Biggest deposits in Trinidad • 100 Acres, • 90 meter deep • 10 to 15 Million MT • Pen - 5 max • Asphalt found in France, Italy & Switzerland - Rock Asphalt.
Bitumen • Conventional Bitumen • Paving Grade Bitumen • Industrial Grade Bitumen • Cutback • Bitumen Emulsions • Modified Bitumen • Modified Bitumen Emulsions
COMPOSITION B I T U M E N
Elemental Analysis Carbon 82 - 88 % Hydrogen 8 - 11 % Sulphur 0 - 6 % Oxygen 0 - 1.5 % Nitrogen 0 - 1 %
Handling of BITUMEN
Storage & Handling • Bitumen tanks should have low surface to volume ratio. p r2 1 Exposed surface = pr2h h • Product should be recirculated, however, return lines should enter the tank below Bitumen surface. • Bitumen should always be handled at lowest possible temperature, consistent with efficient use. • In case of reheating, heating should be done intermittently to prevent high localised temperatures. Prolonged direct flame heating may cause cracking of Bitumen.
Normally Bitumen hardens by one grade during mixing and laying.
Selection of GRADE
Selection Criteria • Choice of Bitumen is based on • Climatic Conditions - Maximum & Minimum temperature & rainfall. • Intensity of Traffic - Number of vehicles per day, Traffic speed & axle load of vehicles.
Applications of 80/100 Grade • Less viscous grade. • Used in all climatic conditions. • Suited for traffic load < 1500 cv/day. • Better suited for high altitude/snow bound regions irrespective of traffic intensity.
Applications of 60/70 Grade • More viscous grade. • Higher softening point. • Suited for traffic intensity > 1500 cv/day. • Can withstand heavier axle loads. • Better suited for highways, expressways & urban roads. • Suited for areas where difference between min. & max. temp. is > 25oC. • Reduced stripping in presence of water.
Applications of 30/40 Grade • Suited for areas where diff. between min. & max. temp. < 25oC. • Suited for traffic intensity > 1500 cv/ day • Used in metropolitan areas. • Used in airport runways.
Bitumen Advantages
Smooth Safe Economical Speed Quiet Environment friendly Versatile State of-the-art Stage Construction Resistant to de-icing material Serviceability Advantages
Smooth • Better riding quality • Absence of joints • Estimated 15% increase in pavement life for 50% increase in smoothness • Less wear and tear to vehicle • Lesser fuel consumption • Enjoyable ride
Safe • Better skid resistance over a longer period of time • Use of OGFC reduces Tyre Spray, Hydroplaning and Improves Visibility • Better contrast with pavement markings
Economical • Low initial cost compared to PCC • Gap widens throughout pavement life • A well designed and constructed pavement • Can last for 25 to 34 years without reconstruction • Can serve for 15 year or more before distresses become sufficient to require rehabilitation
Speed of Construction • Newark Airport – 1,15,000MT in 15 days, 11,000MT in 24 hours • Pave during off peak hours and open to traffic as soon as it cools down • Reduces work zone accident • Can result in 80% reduction in user delay costs • 24-hour closure will have 3 to 10 times more vehicles pass through the work zone
Quiet Pavements • Dense graded asphalt is quieter by 2 to 3 dB(A) compared to PCC • 3 dB(A) corresponds to • Doubling the distance in the line of source • Reducing traffic volume by 50% • Reducing traffic speed by 25% • Open graded Friction Course • Reduces noise further • Costs 1/8th of noise barrier on side of the road • Aesthetically superior
Environment Friendly • Used for water proofing of fish ponds without any problem • Very low level of leachable compounds • Most recycled product in the world • 100% recyclable • Second highest - Aluminium cans – 60% • Can use waste material from other fields also like worn out PCC
State-of-the-Art • Road design, construction and maintenance methods are being overhauled • New tests being developed • New plants providing high quality materials • Pavers with laser controlled screeds for even smoother pavements • Better material transfer vehicles for uniformity and rollers with increased compactive effort. • The ultimate result of this new technology will be: smoother, more durable, longer lasting asphalt pavements
Stage Construction • Bituminous pavements can be constructed in stages • Being made thicker and/or wider as the need arises • Each successive layer becomes an integral part of the pavement structure, increasing the load carrying capacity.
De-icing Materials • Bituminous pavements are not harmed by de-icing chemicals • Also snow and ice melt quickly from bituminous pavements
Serviceability • Bituminous pavements can easily maintain a high level of serviceability with minimal disruption to the traffic • Can be easily trenched, patched and quickly opened to traffic when underground utilities need to be repaired.
MODIFIED BITUMEN Binder of the future
Why Modified Bitumen? Demands on Road increasing every year • Increasing Number of Vehicles • Increasing Axle Load • Desire to maintain higher serviceability level • Higher fatigue resistance • Higher resistance to weathering • Better adhesion • Higher stiffness modulus • Lesser cracking, ravelling, deformation & creep failure • Reduce number of overlays • Reduction in vehicle operation cost
Why Modified Bitumen? Another view point • 2.75 million vehicles generate discarded tyres • 30,000- 40,000 tyres are disposed every day • 1,00,000 –1,20,000 tyres will be available by 2021 • Use of CRMB in maintenance of roads can consume 3500 Kg/km non-biodegradable waste rubber
Crumb Rubber Modified Bitumen Bitumen + Additives (Modifiers/Treated Crumb Rubber)
Types of Modifiers Synthetic Elastomers SBS, SBR etc. Polymers Plastics Rubbers Crumb Rubber Natural Rubber (Latex) Thermoset Epoxy Resins Plain Thermoplastic LDPE, EVA, EBA Chemically Treated
THERMOPLASTIC ELASTOMERS Styrene-butadiene-styrene(SBS) Styrene-butadiene-rubber (SBR) Styrene-isoprene-styrene (SIS) Styrene-ethylene-butadiene-styrene (SEBS) Ethylene-prppylene-diene terpolymer (EPDM) Isobutene-isoprene copolymer (IIR) Natural Rubber Crumb Rubber Polybutadiene (PBD) Polyisoprene THERMOPLASTIC POLYMERS Ethylene vinyl acetate (EVA) Ethylene methyl acrylate (EMA) Ethylene butyl acrylate (EBA) Atactic polypropylene (APP) Polyethylene (PE) Polypropylene (PP) Polyvinyl chloride (PVC) Polystyrene (PS) THERMOSETTING POLYMERS Epoxy resin Polyurethane resin Acrylic resin Phenolic resin CHEMICAL MODIFIERS Organo-metallic compounds Sulphur Lignin FIBRES Cellulose Alumino-magnesium silicate Glass fibre Asbestos Polyester Polypropylene ADHESION IMPROVERS Orgainc amines Amides ANTIOXIDANTS Amines Phenols Organo-zinc/organo-lead compounds NATURAL ASPHALTS Trinidad lake Asphalt (TLA) Gilsonite Rock asphalt FILLERS Carbon black Hydrated lime Lime Fly ash Types of Modifiers
International Use of Crumb Rubber Modified Bitumen • CRMB is being used in USA from 1960 • Currently Arizona , Florida , Texas and California using 2 million tons of Rubberized Bitumen. • CRMB is very popular in Australia for chip sealing wearing courses and structural layers . • Use of CRMB increasing in developing countries of Latin America.
International Use of Crumb Rubber Modified Bitumen • CRMB in use in USA, Canada, France , Germany and South Africa. • UK Environmentalist’s want use of CRMB to be encouraged on roads. Govts. especially are considering making the use mandatory. • Belgian Road Research center encouraging the use of CRMB on Freeways • South African companies are increasingly using Rubber Modified mixes
Atmospheric Temperature OC Minimum Maximum <35 35-45 >45 <-10 CRMB50 CRMB 55 CRMB 55 -10 to10 CRMB 50 CRMB 55 CRMB 60 >10 CRMB 55 CRMB 55 CRMB 60 Selection Criteria
Bitumen New Trends
Future Trends in Bituminous Roads • ISO Certification of Roads • Road Safety Audit • Performance Based Specifications • Stone Mastic Asphalt • Perpetual Pavements • Foamed Bitumen • Polyphosphoric Acid Modified Bitumen • Sulphur Extended Bitumen Modifiers
No Wonder “The smart choice is HP Bitumen” Thank You!