BITUMENBITUMEN
PAVES THE WAYPAVES THE WAYPAVES THE WAYPAVES THE WAYPAVES THE WAYPAVES THE WAYPAVES THE WAYPAVES THE WAY
Types of BindersTypes of BindersTypes of BindersTypes of BindersTypes of BindersTypes of BindersTypes of BindersTypes of Binders
1. Tar
2. Natural Asphalt / Rock Asphalt / Lake Asphaltp
3. Bitumen
TarTarTarTarTarTarTarTar• 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 / Natural Asphalt / Rock Asphalt / Natural Asphalt / Rock Asphalt / Natural Asphalt / Rock Asphalt / Lake AsphaltLake AsphaltLake AsphaltLake Asphalt
• Naturally occurring Bituminous binder.Bi d i i T i id d• Biggest deposits in Trinidad– 100 Acres,– 90 meter deep– 10 to 15 Million MT– Pen - 5 max
• Asphalt found in France, Italy & S it l d R k A h ltSwitzerland - Rock Asphalt.
BitumenBitumenBitumenBitumenBitumenBitumenBitumenBitumen• Conventional BitumenConventional Bitumen
Paving Grade BitumenIndustrial Grade BitumenIndustrial Grade Bitumen
• Cutback
• Bitumen Emulsions
• Modified Bitumen
M difi d Bit E l i• Modified Bitumen Emulsions
B I T U M E NB I T U M E NB I T U M E NB I T U M E NB I T U M E NB I T U M E NB I T U M E NB I T U M E N
COMPOSITIONCOMPOSITIONCOMPOSITIONCOMPOSITION
Elemental AnalysisElemental AnalysisElemental AnalysisElemental AnalysisElemental AnalysisElemental AnalysisElemental AnalysisElemental Analysis
Carbon 82 - 88 %Hydrogen 8 - 11 %Sulphur 0 - 6 %pOxygen 0 - 1.5 %Nitrogen 0 1 %Nitrogen 0 - 1 %
Chemical CompositionChemical CompositionChemical CompositionChemical CompositionChemical CompositionChemical CompositionChemical CompositionChemical Composition
BitBitBitumenBitumen
A h ltA h ltAsphaltenesAsphaltenes5 to 25% wt.
MaltenesMaltenes
SaturatesSaturates AromaticsAromatics ResinesResinesDecreases Penetration
SaturatesSaturates5 to 20% wt.
AromaticsAromatics40 to 65% wt.
ResinesResines10 to 20% wt.
Increases PenetrationReduces Shear Susceptibility
Increases Softening Point, reduces Penetration Index, p y e e a o de ,increases Viscosity
SpecificationsSpecificationsSpecificationsSpecificationsSpecifications Specifications andand
Specifications Specifications andandandand
T t M th dT t M th dandand
T t M th dT t M th dTest MethodsTest MethodsTest MethodsTest Methods
What is expected from Bitumen?What is expected from Bitumen?What is expected from Bitumen?What is expected from Bitumen?What is expected from Bitumen?What is expected from Bitumen?What is expected from Bitumen?What is expected from Bitumen?
• Ensure road behaves in a predictable way• Ensure road behaves in a predictable way• Bitumen performs the desired function on the road
Does not fail under predictable loads– Does not fail under predictable loads– Resists deterioration of road with time
Is able to withstand expected climatic conditions– Is able to withstand expected climatic conditions– Mix easily and form strong bond with a wide
variety of aggregatesvariety of aggregates– Is safe to handle– Modified Bitumen and Bitumen Emulsions should– Modified Bitumen and Bitumen Emulsions should
be a stable mixture in storage and handling
Penetration TestPenetration TestPenetration TestPenetration TestPenetration TestPenetration TestPenetration TestPenetration Test
• Arbitrary Empirical Number• Arbitrary Empirical Number• Depth of penetration of a
t d d i dl dstandard size needle under standard test conditions
• Very easy to perform at field level
• Helps in classification and traceabilityy
Softening Point TestSoftening Point TestSoftening Point TestSoftening Point TestSoftening Point TestSoftening Point TestSoftening Point TestSoftening Point Test• Arbitrary test to indicate y
the temperature at which bitumen is more of a liquid qand less of a solid
• Higher softening pointsHigher softening points indicate higher resistance to melting on roadto melting on road
• Higher resistance to melting indicates highermelting indicates higher rutting resistance
Ductility TestDuctility TestDuctility TestDuctility TestDuctility TestDuctility TestDuctility TestDuctility Test• Arbitrary empirical test to y p
measure the cohesive strengthg
• Cohesive strength is loosely related to theloosely related to the fatigue strength
• Testing temperatures• Testing temperatures may vary from country to country and from grade tocountry and from grade to grade also
RelationshipRelationshipRelationshipRelationshipRelationshipRelationshipBetweenBetween
RelationshipRelationshipBetweenBetweenBetween Between
PropertiesPropertiesBetween Between
PropertiesPropertiesPropertiesPropertiesPropertiesProperties
Penetration at
Softening Point – 800 Penetration
at Fraass Breaking Pt
– 1.25InterdependenciesInterdependenciesInterdependenciesInterdependencies
Viscosityat
Softening PointSoftening Point -1200 Pa s
(12000 poise) ( p )
Bitumen Test Data ChartBitumen Test Data ChartBitumen Test Data ChartBitumen Test Data Charttu e est ata C a ttu e est ata C a ttu e est ata C a ttu e est ata C a t
SelectionSelectionSelectionSelectionSelection Selection ofof
Selection Selection ofofofof
GradeGradeofof
GradeGradeG adeG adeG adeG ade
Choice of GradeChoice of GradeChoice of GradeChoice of GradeChoice of GradeChoice of GradeChoice of GradeChoice of Grade
• Choice of Bitumen is based on
Climatic Conditions - Maximum & Mi i t t & i f llMinimum temperature & rainfall.
I i f T ffi N b fIntensity of Traffic - Number of vehicles per day, Traffic speed & axle load of vehiclesaxle load of vehicles.
Applications of 30/40 GradeApplications of 30/40 GradeApplications of 30/40 GradeApplications of 30/40 GradeApplications of 30/40 GradeApplications of 30/40 GradeApplications of 30/40 GradeApplications 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 metropolitan areas.• Used in airport runways.
Applications of 60/70 GradeApplications of 60/70 GradeApplications of 60/70 GradeApplications of 60/70 GradeApplications of 60/70 GradeApplications of 60/70 GradeApplications of 60/70 GradeApplications of 60/70 Grade• More viscous grade.g• Higher softening point.• Suited for traffic intensity > 1500 cv/day• 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.p• Reduced stripping in presence of water.
Applications of 80/100 GradeApplications of 80/100 GradeApplications of 80/100 GradeApplications of 80/100 Grade
• Less viscous grade.g• Used in all climatic conditions.
S it d f t ffi l d < 1500 /d• Suited for traffic load < 1500 cv/day.• Better suited for high altitude/snow bound g
regions irrespective of traffic intensity.
HandlingHandlingHandling Handling
ofof
BitBitBitumenBitumen
Aging of BitumenAging of BitumenAging of BitumenAging of BitumenAging of BitumenAging of BitumenAging of BitumenAging of Bitumen
• Bitumen undergoes a process of• Bitumen undergoes a process of aging with time– Becomes harder and brittle
• Factors affecting aging of bitumenFactors affecting aging of bitumen– High Temperature
A il bilit f O– Availability of Oxygen– Exposure to UV radiation
Aging of BitumenAging of BitumenAging of BitumenAging of Bitumeng gg gg gg g
Optimal Viscosity for Mixing & CompactionOptimal Viscosity for Mixing & CompactionOptimal Viscosity for Mixing & CompactionOptimal Viscosity for Mixing & Compaction
N ll Bit h d Normally Bitumen hardens by one grade during by one grade during mixing and laying.m x ng and lay ng.
MODIFIED BITUMENMODIFIED BITUMENMODIFIED BITUMENMODIFIED BITUMENBinder ofBinder ofBinder of th f tBinder of th f tthe futurethe future
Why Modified Bitumen?Why Modified Bitumen?Why Modified Bitumen?Why Modified Bitumen?Why Modified Bitumen?Why Modified Bitumen?Why Modified Bitumen?Why Modified Bitumen?Demands on Road increasing every yearg y y
Increasing Number of VehiclesIncreasing Axle Load gDesire to maintain higher serviceability level
Higher fatigue resistanceHigher resistance to weatheringBetter adhesionHigher stiffness modulusLesser cracking, ravelling, deformation & creep failurefailureReduce number of overlays
Reduction in vehicle operation costReduction in vehicle operation cost
Crumb Rubber ModifiedCrumb Rubber ModifiedCrumb Rubber ModifiedCrumb Rubber ModifiedCrumb Rubber Modified Crumb Rubber Modified BitumenBitumen
Crumb Rubber Modified Crumb Rubber Modified BitumenBitumen
BitumenBitumenBitumenBitumen++
Additives Additives
(Modifiers/Treated Crumb Rubber)(Modifiers/Treated Crumb Rubber)( )( )
Types of ModifiersTypes of ModifiersSynthetic Elastomers
SBS, SBR etc.
P l R bbPlastics
,
Polymers RubbersPlastics
Crumb RubberNatural Rubber(Latex)
ThermosetEpoxy Resins
(Latex)
Thermoplastic Chemically Plain
LDPE, EVA, EBA Treated
Selection CriteriaSelection CriteriaSelection CriteriaSelection CriteriaSelection CriteriaSelection CriteriaSelection CriteriaSelection Criteria
Atmospheric Temperature OCAtmospheric Temperature OCMinimum Maximum
<35 35 45 >45<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
Methods of ClassificationMethods of ClassificationMethods of ClassificationMethods of ClassificationMethods of ClassificationMethods of ClassificationMethods of ClassificationMethods of Classification
Methods of ClassificationMethods of ClassificationMethods of ClassificationMethods of Classification
PenetrationPenetration Viscosity Viscosity of TFOTof TFOTViscosityViscosity PerformancePerformance
Penetration Based SystemPenetration Based SystemPenetration Based SystemPenetration Based SystemPenetration Based SystemPenetration Based SystemPenetration Based SystemPenetration Based System• More than 100 years oldMore than 100 years old• Has stood the test of time• Based on Penetration at 25 OC• Penetration 30 to 100 are suitable for roadPenetration 30 to 100 are suitable for road
constructionH d d it bl f h i t ffi l d• Harder grades suitable for heavier traffic loads
• Softer grades suitable for light traffic loadsSofter grades suitable for light traffic loads
Viscosity Based SystemViscosity Based SystemViscosity Based SystemViscosity Based SystemViscosity Based SystemViscosity Based SystemViscosity Based SystemViscosity Based System
• Viscosity is considered to be the primary propertyproperty
• Most tests over lap with that of Penetration based classification
• Classified as VG 10 20 30 and 40 basedClassified as VG 10, 20, 30 and 40 based on viscosity at 60OC
Viscosity of TFOT Residue Based Viscosity of TFOT Residue Based S tS t
Viscosity of TFOT Residue Based Viscosity of TFOT Residue Based S tS tSystemSystemSystemSystem
• Simulates aging of Bitumen• Viscosity ranging from 40 to 700 pascalViscosity ranging from 40 to 700 pascal
seconds at 60OC are suitable for road constructionconstruction
• Most tests overlap with that of Penetration based classification
• Higher viscosity for higher traffic and low• Higher viscosity for higher traffic and low viscosity for lower traffic
PERFORMANCE PERFORMANCE PERFORMANCE PERFORMANCE GRADE BITUMENGRADE BITUMENGRADE BITUMENGRADE BITUMEN
BITUMEN TODAYBITUMEN TODAYBITUMEN TODAYBITUMEN TODAY• Penetration/Viscosity based classification• 80/100, 60/70, 30/40• Penetration, Softening Point, Ductility, Viscosity
E i i l t t d t t d d t l di t• Empirical tests done at standard temp., loading, etc.• Ageing is not considered• No direct correlation with actual field conditionsNo direct correlation with actual field conditions • Seems to work somehow – Has stood the test of
timeN d t t i ffi i i C t ff ti• Need to cut inefficiencies – Cost effective
More direct correlation between bitumen andMore direct correlation between bitumen andMore direct correlation between bitumen and road performance is needed
More direct correlation between bitumen and road performance is needed
BITUMEN TOMORROWBITUMEN TOMORROWBITUMEN TOMORROWBITUMEN TOMORROWBITUMEN TOMORROWBITUMEN TOMORROWBITUMEN TOMORROWBITUMEN TOMORROW• More direct correlation between road performance and
ti f bitproperties of bitumen• Properties desired
– Easier handling (mixing, coating, rolling) – Better rutting resistance– Higher fatigue life– Resistance to low temperature cracking
- New system of classification to be developed
- New tests to be developed
CLASSIFICATIONCLASSIFICATIONCLASSIFICATIONCLASSIFICATION
PG 58 22PG 58 22PG 58 -22PG 58 -22
Mi tPerformance Grade
Min. pavement design temp.
Average 7 day max. pavement design temp.pavement design temp.
MIXING AND LAYINGMIXING AND LAYINGMIXING AND LAYINGMIXING AND LAYING
• Tested in rotational viscometer
• Max viscosity of 3 Pa-s atMax. viscosity of 3 Pa s at 135oC
AGEING OF BITUMENAGEING OF BITUMENAGEING OF BITUMENAGEING OF BITUMENAGEING OF BITUMENAGEING OF BITUMENAGEING OF BITUMENAGEING OF BITUMEN
• During Construction• Early in Pavement’s life• Early in Pavement s life
– Post construction upto two years
• Late in pavement’s life
Rotating thin film oven test (RTFOT)
• Late in pavement s life– Seven plus years of life
RTFOT + Pressure Ageing V l (PAV)Vessel (PAV)
ROTATING THIN FILM OVEN TESTROTATING THIN FILM OVEN TESTROTATING THIN FILM OVEN TESTROTATING THIN FILM OVEN TESTROTATING THIN FILM OVEN TESTROTATING THIN FILM OVEN TESTROTATING THIN FILM OVEN TESTROTATING THIN FILM OVEN TEST
PRESSURE AGEING VESSELPRESSURE AGEING VESSELPRESSURE AGEING VESSELPRESSURE AGEING VESSELPRESSURE AGEING VESSELPRESSURE AGEING VESSELPRESSURE AGEING VESSELPRESSURE AGEING VESSEL
RUTTINGRUTTINGRUTTINGRUTTINGRUTTINGRUTTINGRUTTINGRUTTING
• Due to melting of bitumen on the roadDue to melting of bitumen on the road• Always occurs at max. pavement temp.
T t t b d t d t t• Test to be conducted at max. pavement temp.
• Tested in Dynamic Shear Rheometer• G*/Sinδ min. 1 kPa, @ 10 rad/s for unaged , @ g
bitumen• G*/Sinδ min. 2.2 kPa, @ 10 rad/s forG /Sinδ min. 2.2 kPa, @ 10 rad/s for
RTFOT aged bitumen
DYNAMIC SHEAR RHEOMETERDYNAMIC SHEAR RHEOMETERDYNAMIC SHEAR RHEOMETERDYNAMIC SHEAR RHEOMETERDYNAMIC SHEAR RHEOMETERDYNAMIC SHEAR RHEOMETERDYNAMIC SHEAR RHEOMETERDYNAMIC SHEAR RHEOMETER
FATIGUEFATIGUEFATIGUEFATIGUE
• Due to repeated loading unloading• Due to repeated loading,unloading cycles
• Always occurs near the averageAlways occurs near the average pavement temp.
• Test to be conducted at average + 4OCTest to be conducted at average + 4 C pavement temp.
• Tested in Dynamic Shear RheometerTested in Dynamic Shear Rheometer• G*Sinδ max. 5000 kPa, @ 10 rad/s for
RTFOT + PAV aged bitumenRTFOT + PAV aged bitumen
LOW TEMP CRACKINGLOW TEMP CRACKINGLOW TEMP CRACKINGLOW TEMP CRACKING
• Due to loss of elasticity at very low temp• Due to loss of elasticity at very low temp.• Always occurs at lowest pavement temp.
T ti d t i t 10OC• Testing done at min. temp. + 10OC • Bending Beam Rheometer• Creep Stiffness of max. 300,000 kPa, m-
value min. 0.30• Direct Tension Test - For Modified
Bitumens• Failure strain min. 1%
BENDING BEAM RHEOMETERBENDING BEAM RHEOMETERBENDING BEAM RHEOMETERBENDING BEAM RHEOMETERBENDING BEAM RHEOMETERBENDING BEAM RHEOMETERBENDING BEAM RHEOMETERBENDING BEAM RHEOMETER
DIRECT TENSILE TESTERDIRECT TENSILE TESTERDIRECT TENSILE TESTERDIRECT TENSILE TESTERDIRECT TENSILE TESTERDIRECT TENSILE TESTERDIRECT TENSILE TESTERDIRECT TENSILE TESTER
PERFORMANCE EVALUATIONPERFORMANCE EVALUATIONPERFORMANCE EVALUATIONPERFORMANCE EVALUATIONPERFORMANCE EVALUATIONPERFORMANCE EVALUATIONPERFORMANCE EVALUATIONPERFORMANCE EVALUATION
GRADE BUMPINGGRADE BUMPINGGRADE BUMPINGGRADE BUMPING• Choice of grade depends on max. and min. pavement
temperature 20 mm below road surfacetemperature 20 mm below road surface.• Correction for Traffic speed
– > 90 km/h - No Correction– > 90 km/h - No Correction– < 90 km/h - Increase one high temp. grade
< 20 km/h Increase two high temp grade– < 20 km/h - Increase two high temp. grade • Correction for Traffic volume
< 10 million ESAL No Correction– < 10 million ESAL - No Correction– > 10 million ESAL - Increase one high temp. grade
> 30 million ESAL Increase two high temp grade– > 30 million ESAL - Increase two high temp. grade
Performance Vs TestsPerformance Vs TestsPerformance Vs TestsPerformance Vs TestsPerformance Vs TestsPerformance Vs TestsPerformance Vs TestsPerformance Vs Tests
LLRuttingRutting Fatigue Fatigue
CrackingCracking
Low Low Temperature Temperature
CrackingCracking
Mixing Mixing and and
LayingLaying
Ductility Fraass Breaking Point
Softening P i
Viscosity at
Fatigue Strength
Breaking Point
Creep Stiffness
Rate of change
Point
Viscosity
P t ti
y135OC
Softening Point,
Viscosity &
Rate of change of Creep
Failure Strain
Penetration
Complex Shear
Penetration after Aging
Shear Modulus
SafeSafeHandling PracticesHandling Practices
Health, Safety & Environmental Health, Safety & Environmental A tA t
Health, Safety & Environmental Health, Safety & Environmental A tA tAspectsAspectsAspectsAspects
1 Low order of potential hazard provided good1 Low order of potential hazard provided goodhandling practices are observed.
2 C t i P l li A ti H d b2 Contains Polycyclic Aromatic Hydrocarbons.PCAs with molecular wt. Of 200 to 4500 arebiologically active carcenogensbiologically active carcenogens.Concentration of these in Bitumen isextremely low.
3 Other than heat burns, hazards arenegligible. However it is prudent to avoidg g pprolonged & intimate skin contact.
Health, Safety & Environmental Health, Safety & Environmental Health, Safety & Environmental Health, Safety & Environmental , y, yAspects (contd.)Aspects (contd.)
, y, yAspects (contd.)Aspects (contd.)
4 In case of skin burns plunge the affected areaunder cold running water for 10 minutesunder cold running water for 10 minutes.
5 When bitumen is heated or mixed with5 When bitumen is heated or mixed withaggregate, fumes are emitted. The fumescontain particulate matter, Hydrocarboncontain particulate matter, Hydrocarbonvapours & very small amount of H2S.However, the concentration is rarely aboveHowever, the concentration is rarely abovepermissible limits.
Th k YTh k YTh k YTh k YThank YouThank YouThank YouThank You