ASSTHO T209

WSDOT Materials Manual M 46-01.15 Page 1 of 10 January 2013

WSDOT FOP for AASHTO T 2091

Theoretical Maximum Specific Gravity and Density of Hot-Mix Asphalt Paving Mixtures

1. Scope

1.1 Thistestmethodcoversthedeterminationofthetheoreticalmaximumspecificgravityanddensityofuncompactedhot-mixasphaltpavingmixturesat77°F(25°C).

1.2 ThevaluesstatedinEnglishunitsaretoberegardedasthestandard.

1.3 Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.

2. ReferencedDocuments

2.1 AASHTOStandards

M231–WeighingDevicesUsedintheTestingofMaterials

R61–EstablishingRequirementsforandPerformingEquipmentStandardizationsandChecks

2.2 ASTMStandards

D4311–PracticeforDeterminingAsphaltVolumeCorrectiontoaBaseTemperature

C670–PreparingPrecisionandBiasStatementsforTestMethodsforConstructionMaterials

2.3 OtherStandards

T168–WAQTCFOPforAASHTOforSamplingBituminousPavingMixtures

T712–WSDOTStandardMethodofReducingHotMixAsphaltPavingMixtures

3. Terminology

3.1 Definitions

3.1.1 Density,asdeterminedbythistestmethod.Themassofacubicmeterofthematerialat77°F(25°C)inEnglishunits,orthemassofacubicfootofthematerialat77°F(25°C)ininch-poundunits.

3.1.2 Residualpressure,asemployedbythistestmethod.Thepressureinavacuumvesselwhenvacuumisapplied.

3.1.3 Specificgravity,asdeterminedbythistestmethod.Theratioofagivenmassofmaterialat77°F(25°C)tothemassofanequalvolumeofwateratthesame temperature.

1ThisFOPisbasedonAASHTOT209(2011)andhasbeenmodifiedperWSDOTstandards.Toviewtheredlinemodifications,contacttheWSDOTQualitySystemsManagerat360-709-5412.

Page 2 of 10 WSDOT Materials Manual M 46-01.15 January 2013

T 209 Theoretical Maximum Specific Gravity and Density of Hot-Mix Asphalt Paving Mixtures

4. SummaryofTestMethod

4.1 AweighedsampleofHMApavingmixtureinthelooseconditionisplacedinataredvacuumvessel.Sufficientwaterisaddedtocompletelysubmergethesample.Vacuumisappliedfor15±2mintograduallyreducetheresidualpressureinthevacuumvessel.Attheendofthevacuumperiod,thevacuumisgraduallyreleased.Thevolumeofthesampleofpavingmixtureisobtainedbyfillingthevacuumcontainerlevelfullofwaterandweighinginair.Atthetimeofweighing,thetemperatureismeasuredaswellasthemass.Fromthemassandvolumemeasurements,thespecificgravityordensityat77°F(25°C)iscalculated.Ifthetemperatureemployedisdifferentfrom77°F(25°C),an appropriate correction is applied.

5. SignificanceandUse

5.1 Thetheoreticalmaximumspecificgravitiesanddensitiesofhot-mixasphaltpavingmixturesareintrinsicpropertieswhosevaluesareinfluencedbythecompositionofthemixturesintermsoftypesandamountsofaggregatesandasphaltbindermaterials.

5.1.1 ThesepropertiesareusedtocalculatepercentairvoidsincompactedHMA.

5.1.2 ThesepropertiesprovidetargetvaluesforthecompactionofHMA.

5.1.3 ThesepropertiesareessentialwhencalculatingtheamountofasphaltbinderabsorbedbytheinternalporosityoftheindividualaggregateparticlesinHMA.

6. Apparatus

6.1 Followtheproceduresforperformingequipmentstandardizations,standardization,andchecksfoundinR61.

6.2 VacuumContainer

6.2.1 Thevacuumcontainersdescribedmustbecapableofwithstandingthefullvacuumapplied,andeachmustbeequippedwiththefittingsandotheraccessoriesrequiredbythetestprocedurebeingemployed.TheopeninginthecontainerleadingtothevacuumpumpshallbecoveredbyapieceofNo.200(75-μm)meshtominimizethelossoffinematerial.

6.2.2 Thecapacityofthevacuumcontainershouldbebetween2000and10,000-mLanddependsontheminimumsamplesizerequirementsgiveninSection7.2. Avoidusingasmallsampleinalargecontainer.

6.2.3 VacuumBowl–Eitherametalorplasticbowlwithadiameterofapproximately7.1to10.2in(180to260mm)andabowlheightofatleast6.3in(160mm)equippedwithatransparentcoverfittedwitharubbergasketandaconnectionfor the vacuum line.

6.2.4 VacuumFlaskforWeighinginAirOnly–Athick-walledvolumetricglassflaskandarubberstopperwithaconnectionforthevacuumline.

6.2.5 PycnometerforWeighinginAirOnly–Aglass,metal,orplasticpycnometer.


Theoretical Maximum Specific Gravity and Density of Hot-Mix Asphalt Paving Mixtures T 209

6.3 Balance,conformingtotherequirementsofAASHTOM231,ClassG2.Thebalanceshallbestandardizedatleastevery12months.

6.3.1 Forthemassdetermination-in-watermethod,thebalanceshallbeequippedwithasuitableapparatusandholdertopermitdeterminingthemassofthesamplewhilesuspendedbelowthebalance.Thewiresuspendingtheholdershallbethesmallestpracticalsizetominimizeanypossibleeffectsofavariableimmersedlength.

6.4 Vacuumpumporwateraspirator,capableofevacuatingairfromthevacuumcontainertoaresidualpressureof30mmHg(4.0kPa)orless.

6.4.1 Whenavacuumpumpisused,asuitabletrapofoneormorefilterflasks,orequivalent,shallbeinstalledbetweenthevacuumvesselandvacuumsourcetoreducetheamountofwatervaporenteringthevacuumpump.

6.5 Absolutepressuregaugeorvacuumgauge,usedforannualstandardizationandtraceabletoNIST(mandatory)tobeconnecteddirectlytothevacuumvesselandtobecapableofmeasuringresidualpressuredownto30mmHg(4.0kPa),orless(preferablytozero).Itistobeconnectedattheendofthevacuumlineusinganappropriatetubeandeithera“T”connectoronthetopofthevesselorbyusingaseparateopening(fromthevacuumline)inthetopofthevesseltoattachthehose.

Note 2: Aresidualpressureof30mmHg(4.0kPa)absolutepressureisapproximatelyequivalentto730mmHg(97kPa)readingonvacuumgaugeatsealevel.

6.6 Bleedervalve,attachedtothevacuumtraintofacilitateadjustmentofthevacuumbeingapplied to the vacuum vessel.

6.7 Thermometricdevice(massdeterminationinair),liquid-in-glassthermometers,orothersuitablethermometricdevice,accurateto1ºF(0.5ºC).Thethermometricdeviceshallbestandardizedatthetesttemperatureatleastevery12months.

6.8 Waterbaththatcanbemaintainedataconstanttemperaturebetween73and82.9°F(22.8and28.3°C).

6.9 Protectivegloves,usedwhenhandlingglassequipmentundervacuum.

6.10 Mallet,witharubberorrawhidehead.

7. Sampling

7.1 ObtainthesampleinaccordancewithWAQTCFOPforAASHTOT168andWSDOTT712.

7.2 ThesizeofthesampleshallconformtotherequirementsinTable1.Sampleslargerthanthecapacityofthecontainermaybetestedaportionatatime.



Nominal Maximum Aggregate Size, in (mm)

Minimum Sample Size, lb (g)

1½ (37.5) or greater 8 (4000)¾ (19) to 1 (25) 5 (2500)

½ (12.5) or smaller 3 (1500)

Minimum Sample SizesTable 1

8. StandardizationofFlasks,Bowls,andPycnometers

ThissectionhasbeendeletedbyWSDOTandreplacedwiththefollowing:

ThevolumetricflaskormetalvacuumpycnometerwillbestandardizedperiodicallyinconformancewithestablishedverificationproceduresorperAASHTOT209.Standardizationshallbedoneat77°F.

9. SamplePreparation

9.1 SeparatetheparticlesoftheHMAsamplebyhand,takingcaretoavoidfracturingtheaggregate,sothattheparticlesofthefineaggregateportionarenotlargerthan¼in(6.3mm).IfanHMAsampleisnotsufficientlysofttobeseparatedmanually,placeitinaflatpan,andwarmitinanovenuntilitcanbeseparatedasdescribed.

9.2 WSDOThasdeletedthissection.

9.3 Coolthesampletoroomtemperatureandplaceitinataredandstandardizedflask,bowl,orpycnometer.WeighanddesignatethenetmassofthesampleasA.Addsufficientwateratatemperatureofapproximately25°C(77°F)tocoverthesamplecompletely.

Test Method A – Mechanical Agitation

10. Apparatus

10.1 InadditiontotheapparatuslistedinSection6,thefollowingapparatusisrequiredforMethodA.

10.1.1 Mechanicalshaker-shakerforremovingairfromasphaltmix.

11. Procedure

11.1 Removeairtrappedinthesamplebyapplyinggraduallyincreasedvacuumuntiltheabsolutepressuregaugeorvacuumgaugereads30mmHGorless(4.0kPaorless).Maintainthisresidualpressurefor15±2min.Agitatethecontainerandcontentsusingthemechanicaldeviceduringthevacuumperiod.Glassvesselsshouldbeshakenonaresilientsurfacesuchasarubberorplasticmat,andnotonahardsurface,soastoavoidexcessiveimpactwhileundervacuum.Toaidinreleasingthetrappedairfromthemetalvacuumpycnometer,tapthesidesofthemetalvacuumpycnometer3to5timeswiththemalletatapproximatelytwo-minuteintervals.

Note:Thereleaseofentrappedairmaybefacilitatedbytheadditionofafewdropsofsuitablewettingagent.



11.2 Attheendofthevacuumperiod,releasethevacuumwithin10to15seconds.Startthe9to11minutetime,asdescribedinSection13.2,immediatelyuponstartingthereleaseofvacuum.ProceedtoSection13.2.

Test Method B – Manual Agitation

12. Procedure

12.1 Removeairtrappedinthesamplebyapplyinggraduallyincreasedvacuumuntiltheabsolutepressuregaugeorvacuumgaugereads30mmHGorless(4.0kPaorless).Maintainthisresidualpressurefor15±2min.Agitatethecontainerandcontentsduringthevacuumperiodbyvigorousshakingatintervalsofabout2minutes.Glassvesselsshouldbeshakenonaresilientsurfacesuchasarubberorplasticmat,andnotonahardsurface,soastoavoidexcessiveimpactwhileundervacuum.

12.2 Attheendofthevacuumperiod,releasethevacuumwithin10to15seconds.Startthe9to11minutetime,asdescribedinSection13.2immediatelyuponstartingthereleaseofvacuum.ProceedtoSection13.2.

13. MassDetermination

13.1 WSDOThasdeletedthissection.

13.2 MassDeterminationinAir–Filltheflaskoranyoneofthepycnometerswithwaterandadjustthecontentstoatemperatureof77±2°F(25±1°C)inaconstanttemperaturewaterbath.Determinethemassofthecontainer(andcontents),completelyfilled,9to11minutesafterstartingSection11.2 or 12.1.DesignatethismassasE.Accuratefillingmaybeensuredbytheuseofaglasscoverplate.

Inlieuofaconstanttemperaturewaterbathdescribedabove,determinethetemperatureofthewaterwithintheflaskormetalvacuumpycnometeranddeterminetheappropriatedensitycorrectionfactor“R”usingTable2.

14. Calculation

14.1 Calculatethetheoreticalmaximumspecificgravityofthesampleat77°F(25°C)asfollows:

14.1.1 WSDOThasdeletedthissection.

14.1.2 WeighingMassDeterminationinAir

TheoreticalMaximumSpecificGravity= A A+D–E

Where:A = Massofoven-drysampleinair,gD = Massofcontainerfilledwithwaterat77°F(25°C),gE = Massofcontainerfilledwithsampleandwaterat77°F(25°C),g



14.1.3 Ifthetesttemperaturedifferssignificantlyfrom77°F(25°C),correctforthermaleffectsasfollows:

WSDOThasremovedtheAASHTOcalculationandreplaceditwiththefollowingcalculations:

a. Determinationusingtemperaturecorrection:

TheoreticalMaximumGravity= A ×R A+D–EWhere:

A = Massofoven-drysampleinair,g;D = Massofcontainerfilledwithwaterat77°F(25°C),g;andE = Massofcontainerfilledwithsampleandwaterat77°F(25°C),g.R = FactorfromTable2tocorrectdensityofwaterfromthetest

temperatureto77°F(25°C).

Note:Theflaskstandardizationisdoneat77±0.4°F(25±0.2°C).

C° F° “R” C° F° “R”22.8 73.0 1.00054 25.2 77.4 0.9999523.0 73.4 1.00050 25.4 77.7 0.9999023.2 73.8 1.00045 25.6 78.1 0.9998423.3 73.9 1.00042 25.8 78.4 0.9997923.4 74.1 1.00040 26.0 78.8 0.9997423.6 74.5 1.00035 26.1 79.0 0.9997123.8 74.8 1.00030 26.2 79.2 0.9996823.9 75.0 1.00028 26.4 79.5 0.9996324.0 75.2 1.00025 26.6 79.9 0.9995824.2 75.6 1.00020 26.7 80.1 0.9995524.4 75.9 1.00015 27.2 81.0 0.9994124.6 76.3 1.00010 27.3 81.1 0.9993824.8 76.6 1.00005 27.8 82.0 0.9992425.0 77.0 1.00000 28.3 82.9 0.99910

Density Correction Factor “R”Table 2

b. Determinationusingweightedaverage:

WeightedAverageMaximumSpecificGravity =

(Sp.G1 ×A1)+(Sp.G2 ×A2) (A1+A2)

Where:Sp.G1 = SpecificgravityoffirsttestsegmentSp.G2 = SpecificgravityofsecondtestsegmentA1andA2 = Massofdrysampleinairofrespectivetestsegments



14.2 TheoreticalMaximumDensity(Rice)at77°F(25°C)

14.2.1 Calculatethecorrespondingtheoreticalmaximumdensityat77°F(25°C)asfollows:

Theoreticalmaximumdensityat77°F(25°C)=theoreticalmaximumspecificgravity×62.245lb/ft3ininch-poundunits(or997.1kg/m3inSIunits).

Where: Thespecificgravityofwaterat77°F(25°C)=62.245ininch-poundunits (or997.1inSIunits).

15. SupplementalProcedureforMixturesContainingPorousAggregate

WSDOThasremovedthissection.

16. Report

16.1 Reporttheresultsusingoneofthefollowing:

• MaterialsTestingSystem(MATS)

• DOTForm350-092and350-157

• FormapprovedinwritingbytheStateMaterialsEngineer

16.2 ReporttheTheoreticalMaximumSpecificGravity(Gmm)tothreedecimalplaces.ReporttheTheoreticalMaximumDensityto0.1lb/ft3.

17. Precision

SeeAASHTOT209forPrecision.



Appendix(NonmandatoryInformation)

A1.TheoreticalMaximumSpecificGravityforaLoose-PavingMixture

WSDOThasremovedthissection.


Performance Exam ChecklistTheoretical Maximum Specific Gravity and Density of Hot Mix Asphalt Paving Mixtures FOP for AASHTO T 209

ParticipantName________________________________ ExamDate____________________

Procedure Element Yes No1. Thetesterhasacopyofthecurrentprocedureonhand? 2. Allequipmentisfunctioningaccordingtothetestprocedure,andifrequired,

hasthecurrentstandardization/verificationtagspresent?

3. Particlesofsampleseparated? 4. Careusednottofracturemineralfragments? 5. Afterseparation,fineHMAparticlesnotlargerthan¼inch? 6. Sampleatroomtemperature? 7. Massofbowlorflaskdetermined? 8. Massofsampleandbowlorflaskdetermined? 9. Massofsampledetermined? 10. Wateratapproximately77°F(25°C)addedtocoversample? 11. Entrappedairremovedusingpartialvacuumfor15±2min? 12. Containerandcontentsagitatedcontinuouslybymechanicaldeviceormanually

byvigorousshakingatintervalsofabout2minutes?

13. Formetalpycnometer,strike3to5timeswithamallet? 14. Releaseofentrappedairfacilitatedbyadditionofsuitablewettingagent(optional)? 15. Vacuumreleasedwithin10to15seconds. 16. Flaskdetermination:

a. Flaskfilledwithwater? 1. Flaskthenplacedinconstanttemperaturewaterbath(optional)or? 2. Temperatureofwaterinflaskdetermineduponcompletionof16b?

b. Contentsat77±2°FordensityofwatercorrectedusingTable2inFOP? c. Massoffilledflaskdetermined9to11minutesafterremovalofentrapped

aircompleted?

17. Allcalculationsperformedcorrectly?

FirstAttempt: Pass Fail SecondAttempt: Pass Fail

SignatureofExaminer



Comments: