Performance Based Specification for High RAP …...2015/10/21 · High RAP Mixes in Cold Climates...
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Performance Based Specification for High RAP Mixes in Cold Climates Andrew Hanz – MTE Services Inc. Ervin Dukatz – Mathy Construction Gerald Reinke – MTE Services Inc. Northeast Asphalt User Producer Group Meeting October 21, 2015
Transcript of Performance Based Specification for High RAP …...2015/10/21 · High RAP Mixes in Cold Climates...
PerformanceBasedSpecificationforHighRAPMixesinColdClimates
AndrewHanz– MTEServicesInc.ErvinDukatz– MathyConstructionGeraldReinke– MTEServicesInc.
NortheastAsphaltUserProducerGroupMeetingOctober21,2015
Acknowledgements
• MTEStaff– SteveEngber,DougHerlitzka,AlexEngstler
• WisDOT HighRAMCommittee– ChairedbyBarryPaye,WisDOT andDebSchwerman,WAPA
WisDOT HighRecyclePilotProgram• ProposedtoWisDOT managementbyindustryinwinterof2013.– PavementSustainability– EconomicBenefits
• Specificationwasdevelopedfor2014constructionseasonandmodifiedfor2015.– Includesperformancetestsandmixdesignchanges.
• 4projectslet.Twowereconstructedin2014,twoin2015.
HighRAMSPVMixDesignChanges
Material Lower Lift UpperLift*RAS 25 20RAM(max5%RASbywt.of agg.) 50 40
Maximum%BinderReplacement(PBR)
*ReduceupperandlowerplanPGgradebyonegradeforPBR>25%(i.e.PG58-28becomesPG52-34)
MixDesignandQC• DesignAirVoidsdecreasedfrom4.0%to3.5%• TSRincreasedfrom0.70to0.75• IncreasemaximumDusttoBinderRatioto1.6• Adddailymonitoringofasphaltcontentviaextraction.
WisDOT SPV- SelectedPerformanceTestsRuttingHamburg
FatigueSemi-CircularBend
HT(50°C)IT(25°C)LT(-18or-24°C)
ThermalCrackingDC(t)
LongTermAging– AASHTOR30(5daysat85°C)• SCBandDCT• RecoveredbindergradeandΔTc
TestingRequirements• Timingofsubmittals– Preliminary:MixDesignandTestStrip– Construction:1st 600tonandevery10ktonafter.
• LogisticalChallenges– Agencyapprovalofmixdesignandteststripresultsrequired.
–Minimumtimelagbetweenteststripandconstruction~10days.
STH77ProjectOverview
• DesignHighPBRMixesUsingRAP
• Meetorexceedperformanceofstandardmix
• Meetperformancetestingrequirementsforrutting,fatigue,andthermalcracking.
ProjectOverview:• 13Miles• 9 MilesStandard- E3Mixture• 4 MilesHighRAMSPV- E3Mixture• 60KTonTotal(16KHighRAM)• Table460.2Modified– TargetAV=3.5%
PavementSectionDetailsLocation:AshlandCounty- ClamLaketoSTH13• StandardMix~9.5miles– 3”pavementdepth– 1.25”LevelingLayer12.5mmE3PG58-34– 1.75”UpperLayer12.5mmE3PG58-34
• HighRecycleLength– 4.08miles(WestEnd)– 4”totalpavementdepth– 2.25”LowerLayer19mmE3HighRecycle– 1.75”UpperLayer12.5mmE3HighRecycle
• ConstructedinAugust/Septof2014.
ApproachtoProjectMaterialsSelectionandMixDesign
• Obtainmillingsfromproject.• Extract/RAMbinderanddeterminetruePG.
1.Characterize
RAP
• ApplyBlendingCharts:TargetPG58-34.• VirginGradeBinder:PG52-40,-40grademadewithbio-derivedoil.
2.DetermineBinder
Properties
• Sameprocessasconventionalmixdesign.• TargetAVis3.5%forhighRAM.
3.VolumetricMixDesign
ApproachtoProjectPerformanceTesting
• Inmixdesigncompactpillto6.5%AV• 5DaysAgingat85°C,extractandrecoverbinder.• TargetisPG58-34,ΔTc>-5.0°C
4.VerifyBinder
Properties
• BaseBinder (Plan)=PG52-40,alsoSPVairvoidsresultinhighertotalbindercontent.
• ModifybindertoPG58-40toimproveHamburgresults.
5.EvaluateHamburg
• 5DaysAgingat85°C– CompactedMixture• Mixture:SCB@25°C,DCT@-24°C,FractureEnergy>400J/m2
6.CrackingResistance
Results– RecoveredLTPG
LabBlendsforInitialFormulation• 19.0mm:60%PG58-40+40%RAPfromSTH77• 12.5mm:70%PG58-40+30%RAPfromSTH77
-46.0
-44.0
-42.0
-40.0
-38.0
-36.0
-34.0
-32.0
-30.0
-28.0PG58-40PAV
RAP+PG58-40_PAVOnly
RAP+PG58-40_RTFO+PAV MixDesign TestStrip* Prod.#1 Prod.#2
LTPGGrad
e(°C)
19mm(45.9%PBR) 12.5mm(36.7%PBR)
Design Production
Max.LTPGGrade
PG58-40PAVNoRAP
Results– RecoveredBinderΔTc
-5.0
-4.0
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
PG58-40PAV
RAP+PG58-40_PAVOnly
RAP+PG58-40_RTFO+
PAV MixDesign TestStrip* Prod.#1 Prod.#2
ΔTc=
S(60)-m(60)
19mm(45.9%PBR) 12.5mm(36.7%PBR)
Design Production
WisDOT Requirement:ΔTc≥-5°C
MixPerformanceResultsHamburgat50°C
0.0
2.5
5.0
7.5
10.0
12.5
15.0
Mix Design Test Strip Production 1 Production 2
Rut
Dep
th (m
m)
12.5 mm 19mm
WisDOT Maximum
RutDepthat5000passes.
MixPerformanceResultsSCB@25°C
0.00
0.25
0.50
0.75
Mix Design Test Strip Production 1 Production 2
Jc (k
J/m
2)
12.5 mm 19mm
PossibleMinimumLimit
MixPerformanceResultsDCT@-24°C
0
100
200
300
400
500
600
700
800
Mix Design Test Strip Production 1 Production 2
Frac
ture
Ene
rgy
(J/m
2)
12.5 mm 19mm
PointsforDiscussion
1. SCBTestTemperatureSelection– Constantorbasedonclimate?
2. AlternativeLongTermAgingMethods– Loosemixagingat12to24hrs.
3. ComparisontotheControl‒ Focusonrecoveredbinderpropertiesand
crackingtests.
SCBTestTemperatureSelectionLSUResearchReport11-3B
• ITPGofasphaltusedinthestudyrangesfrom25°Cto34°C.• RecommendsJc >0.5kJ/m2forPG76andlower.• Limitestablishedbasedonrelationtofieldperformance.
SCB@25°C
WisDOT PilotProjectResults15°Cvs.25°C
0.510.42
0.54 0.56
0.000.100.200.300.400.500.60
19.0mmProd.1
19.0mmProd.2
12.5mmProd.1
12.5mmProd.2
Jc(k
J/m2)
15C 25C
SCBTemperatureSelection• Whentesttemperaturewasadjustedto15°CforWisDOT mixes,Jc valueswereconsistentwithLSUrecommendations.
• Recommendation– SelectSCBtesttemperaturebasedonclimateusingLTTPBindandcalculationforintermediatetemperaturePG.
• ForWisconsin– NorthernhalfisaPG58-34:SCBtemp=16°C– SouthernhalfisaPG58-28:SCBtemp=19°C
MixtureLongTermAging
• IssueswithAASHTOR30(5days@85°C)– Aginggradientwithdepthinsample.– Sampledimensionschangeduetocreep.– Timerequirements,particularlywhenappliedtoaconstructionproject.
• Proposedalternative:– Loosemixagingat135°Cfor12to24hours.– BasedonAAPTpaperbyBraham(2009)andfurtherworkbyPhilBlankenshipatAI.
LooseMixAgingat135°CEffectofAgingTimeonDCT
Braham,Buttlar,Clyne,“TheEffectofLaboratoryAgingonHotMixAsphaltFractureEnergy.”AAPT2009.
BinderEvaluationforHighRAMMixesDirectMeasurement
– 4mmPP
EffectofAging
0.00.51.01.52.02.53.03.54.0
OB RTFO PAV1 PAV2
Rheo
logicalInd
ex(R
)
20%RAS+5%Oil1 20%RAS+5%Oil2PGGrading
-40.0
-34.0
-28.0
-22.0
-16.0OB RTFO PAV1 PAV2
Bind
erLT
PGGrad
e
20%RAS+5%Oil1 20%RAS+5%Oil2
1. Anderson,etal.,“BinderCharacterizationandEvaluation– Volume3:PhysicalCharacterization.”SHRPA-369Report,NationalResearchCouncil,1994.
2. Farrar,Sui,etal.4mmPlateDevelopment– TRB2011,2012,Eurobitume 2012andothers.
EvaluationofLooseMixAgingBinderProperties
-36.0-34.0-32.0-30.0-28.0-26.0-24.0-22.0
19mm(45.9%PBR) 12.5mm(36.7%PBR)
LTPG(°C)
Prod.#1 Prod.#2 12houraging 24houraging
-5.0
-4.0
-3.0
-2.0
-1.0
0.019mm(45.9%PBR) 12.5mm(36.7%PBR)
ΔTc(°C)
Prod.#1 Prod.#2 12houraging 24houraging
LTPGGrade ΔTc
• ProductionSampleswereagedfor5daysat85°C.AllbindersextractedwithtolueneandrecoveredwithRoto Vap.
• Lowtemperaturepropertiesestimatedusing4mmDSR.• 12hourloosemixagingcorrelateswellwith5dayagingprocedure.
EvaluationofLooseMixAgingMixtureCrackingPerformance
• Performanceissimilarfor5dayagedproductionsamplesand12hr loosemixagedsamples.
• Effectof24houragingnotassevereformixtureperformance,particularlyinDCTtest.
DCT@-24°C
300350400450500550600650700
19mm(45.9%PBR) 12.5mm(36.7%PBR)
FractureEne
rgy(J/
m2)
Prod.#1 Prod#2 12HrLoose 24HrLoose
SCB@15°C
0.30
0.35
0.40
0.45
0.50
0.55
0.60
19mm(45.9%PBR) 12.5mm(36.7%PBR)
Jc(k
J/m2)
Prod.#1 Prod#2 12HrLoose 24HrLoose
Laboratoryvs.FieldAging,(Reinke,2015ETG)12Hr.LooseMix@135°C
MN1-3
MN1-4
MN1-5
y=1.4934x- 0.0519R²=0.98177
-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.01.02.0
-4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0ΔTco
fBinde
rrecovered
from
top1/2inchof
core
ΔTcofBinderrecoveredfrom12hr.,135°CagedloosemixLineofEqualityforrecoveredbinderfrom12hr.,135° agedmixΔTc8yrfieldbinder=F(ΔTc12hr.135°Cloosemix)Linear(ΔTc8yrfieldbinder=F(ΔTc12hr.135°Cloosemix))
Asbinderbecomesmorem-controlled(neg.Tc),thisaging
protocolunder-represents8yearsfieldaginginMinnesota.
Laboratoryvs.FieldAging(Reinke,2015ETG)24Hr.LooseMix@135°C
MN1-3
MN1-4
MN1-5y=0.8497x+0.6405
R²=0.9971
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
-10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0
ΔTco
fBinde
rrecovered
from
top1/2ofco
re
ΔTcofBinderrecoveredfrom24hr.,135°Cagedloosemix
ΔTcRecoveredbinder8yearfieldcores 24hr.135°CagedLineofEqualityLinear(ΔTcRecoveredbinder8yearfieldcores)
Agingprotocolover-predicts8yearsfieldaginginMinnesota.OverpredictionbecomesworseasTc
becomesmorenegative.
MixtureLongTermAging• Loosemixagingatreducedtimesisaviablealternativetocompactedsampleaging.
• Mixturefracturetests,particularlytheDCTshowedlesssensitivitytoagingthanrecoveredbinderproperties.
• Recommendation– Adopt12hrs.loosemixagingat135°CasanalternativemethodforAASHTOR30.
– Continueresearchonrelatingpropertiesoffieldmixestodistress.
WisDOT HighRAMSPVSampleConditioningProtocol
Step TestProcedure Conditioning Reference
1) MixDesign/Volumetrics2hrs + 5min@Compaction
TempAASHTOR30,Section7.1
2)
Hamburg
lab-mixed 4hrs + 5min@135+ 3CAASHTOR30,Section7.2
plantproducedmin.reheattimetoreachCompactionTemp
DCTandSCB
lab-mixedStep1PLUS12hrs + 30min@135+ 3C WisDOT-ModifiedAASHTO
R30,SPVSection7.2plantproduced 12hrs + 30min@135+ 3C
12hourloosemixagingprotocolselectedasanacceleratedagingmethodbasedoncomparisonwith5daycompactedsampleagingat85°C
ComparisontoControlMix• AtaminimumourexpectationwasthatthehighRAMmixwouldperformaswellasconventionalmixesplacedinWI.
• PrimarydistressinWIiscracking,comparisonwillfocuson– Recoveredbindergrading– SCBandDCTtesting– Sensitivitytoaging
ComparisonofMixDesigns
Property ControlMix–12.5mm HighRAM 12.5mm
%BinderReplacement 24.5% 36.7%DesignAirVoid 4.0% 3.5%VMA 15.1% 14.9%Vbe 11.1% 11.4%Dust toBinderRatio 0.90 1.0Asphalt BinderGrade PG58-34 PG58-40MSCR Jnr3.2kPa @58C 3.0 1.1MSCR%R 3.2kPa @58°C 0 43.5%
BinderProperties
-36.0
-34.0
-32.0
-30.0
-28.012 24
LTPG(°C)
HighRAM(37%PBR) Control(25%PBR)
-4.0
-3.0
-2.0
-1.0
0.012 24
ΔTc(°C)
HighRAM(37%PBR) Control(25%PBR)
• HighRAMmixissofterafter12hoursloosemixaging,mixesbehavethesameat24houraging.
Binderrecoveredfrommixessubjectedtoloosemixagingat135°C
DCTResults@-24C
0.0
1.0
2.0
3.0
4.0
5.0
0 0.5 1 1.5 2 2.5 3
MeasuredLoad(kN)
CMOD(fit)(mm)
Loadvs.CMOD(fit)– 12hrLooseMixAging
ControlMixHighRAMMix
Mix Gf: 12Hr LooseMixAging(J/m2)
Gf:24HourLoose MixAging(J/m2)
HighRAM 634.3 70.8 587.5 127.9
Control 296.1 20.4 360.4 5.0
SCBResultsat15°C12HourLooseMixAging
y=-0.0269x+1.3703R²=0.97367
y=-0.0258x+1.2532R²=0.99419
0.000.100.200.300.400.500.600.700.80
25.0 27.0 29.0 31.0 33.0 35.0 37.0 39.0 41.0
StrainEne
rgy(kJ)
NotchDepth(mm)
12HourLooseMixAging
HighRAM(37%PBR) Control(25%PBR) Linear(Control(25%PBR))
Jc HighRAMMix=0.48kJ/m2
Jc ControlMix=0.45kJ/m2
SCBResultsat15°C24hourLooseMixAging
y=-0.0323x+1.4891R²=0.99664
y=-0.0232x+1.11R²=0.99922
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
25.0 28.0 31.0 34.0 37.0 40.0
StrainEne
rgy(kJ)
NotchDepth(mm)HighRAM(37%PBR) ControlMix(25%PBR)
Jc HighRAMMix=0.58kJ/m2
Jc ControlMix=0.40kJ/m2
SCBPostPeakBehavior
Al-Qadi – PresentationatApril2015ETGmeetingFallRiveranddraftAASHTOTP
• AnalysismethodpresentedbyUIUCwasappliedtotheexistingSCBtestdataset.
• MaindifferencesbetweenSCBproceduresaretesttemperature(15°Cvs.25°C),loadingrate(0.5mm/minvs.50mm/min)andnotchdepth(25mmvs.15mm).
A=0.01
FlexibilityIndex– EffectsofMixDesignandAging
0.00.51.01.52.02.53.03.54.0
19.0mm(45%PBR) 12.5mm(37%PBR) 12.5mmControl(25%PBR)
FlexibilityIn
dex
12hrAging 24hrAging
• FlexibilityIndexdiscriminatesbetweenmixturesandtheeffectsofaging.• For12.5mmmix,highRAMperformsbetterthancontrolforbothaging
conditions.Possiblyduetopresenceofpolymeranduseofbiooil.• SubsequentworkatMTEhasimplementedtheformalUIUCdraft
AASHTOprocedure.
STH77ObservationsAfter1Yr.• HighRAMSectionwas
4mileslong.• Controlis9miles.• Overallpavementis
performingwell.
• Veryfewtransversecracks.
• Smallcrackwidth• Nodifferencein
performancebetweensections.
Summary• Goaltomeetorexceedtheperformancepropertiesofthecontrolmixwasachieved.
• ContributingfactorstoperformanceimprovementsforhighRAMmix.– Highereffectivebindercontent/lowerairvoids.– Benefitsofmodificationfrompolymerandbio-derivedoil.
• Effectofagingonmixturecrackingtestsneedsfurtherinvestigation.
NextSteps• WisDOT HighRAMCommitteewillreviewperformancetestingprovisionafter2015constructionseason.
• ContinuestandardizationandevaluationoftheSCBtest.ASTMWK48574
• Continueinvestigationofpost-peakbehaviorinSCBevaluation(UIUCmethod).
• Fall2015– SurveyandcoringofSTH77tocapturefieldperformanceafter1yearinservice.
ThankYou
AndrewHanz,Ph.D.TechnicalDirectorMTEServicesInc.608-779-6352(office)608-780-2509(mobile)[email protected]
