performance -related specifications: integration of the asphalt … · 2020. 1. 28. · performance...

Performance-RelatedSpecifications:IntegrationoftheAsphaltMixture

PerformanceTester(AMPT)DavidJ.Mensching,Ph.D.

OfficeofPreconstruction,Construction,andPavementsNESMEAAnnualConference

Hartford,CTOctober18,2017

• OfficeofPreconstruction,Construction,andPavements

• OfficeofInfrastructureResearchandDevelopment

• OfficeofTechnicalServices

Acknowledgements

• Owneragenciesshortonfunding– Needmorepavementlife– Lessrehab– More“bangforbuck”

• MAP-21introducedperformance-basedadministeringoffederalfunds– FHWAestablishedmeasuresforStatestosetowntargets

Background

• Late 1980s-Early 1990s: Strategic HighwayResearch Program– Superpave mixture design approach– Performance grade binders– But no viable performance tests for mixture

• National Cooperative Highway Research Program– 9-19: Identify simple performance tests for Superpave

(rutting, fatigue)• Dynamic modulus, flow number, flow time

– 9-29: Produce prototype, conduct ruggedness andinterlaboratory studies

• Simple Performance Tester (now known as AMPT)was born!

AMPT– AddressingaNeed

• Temperaturerangefromabout4° to70°C• Computer-controlleddevice

• Softwarebuilt-inforvarioustestprocedures

• Fundamentaltests– Stressandstrainmodeling– “Bulktesting”– PavementMEorFlexPAVETM

• Kitsavailableforothertests

AMPT

Planning&PavementDesign

Specify MixDesign Construct&Accept

Preserve&Rehab

ContinuumofPerformance

PRS

• Asphaltdistress?• Frequencyofsampling/testing?• Howtoquantify/managedata?• Costoflifeloss?• Appropriatemethodstomeasure?

Performance

• Preserveassetsandminimizewholelifecosts

• Operateinafinanciallysustainablemanner

• Providesaframeworktoimproveperformanceonalong-termbasis

• Aplanisnowrequired!

OverviewofAssetManagement

• HowcanIextendpavementlife?– Specificationdevelopment/targets– Exceedingperformancethresholds– Optimizingassetmanagementplan

• HowcanImeasureperformanceupfront?– EffectofRAP,WMA,etc.,andpavementstructure

– Laboratorytestingandconditioning• Fundamental• Index-based• Lotsoftests

TwoQuestions

NeedforUniformity

ContinuumofSpecificationsR

isk

100

QAMethodType of Specification

0End-Result Warranty

Contractor

Owner

Performance

Performance-RelatedSpecifications(PRS)

“QAspecificationsthatdescribethedesiredlevelsofkeymaterialsandconstructionqualitycharacteristics thathavebeenfoundtocorrelatewithfundamentalengineeringpropertiesthatpredictperformance”

TransportationResearchCircularNumberE-C137GlossaryofHighwayQualityAssuranceTerms

IdentifyAQCsandTargetValues

EstablishPerformanceCriteria

ModelPerformance

DesignAQCvs.As-ConstructedAQC

CompareAs-BuiltandAs-Designed

PayFactorTime

Design

Constructed

SOFTWARE

Value of Performance?

HowPRSWorksPlanning

PavementDesign

• Longtermpavementperformancepredictedfromfundamentalengineeringproperties

• Incentivesanddisincentives justifiedthroughreductionorincreaseinpavementlife

• Allowcontractorstobemoreinnovativeandmorecompetitive

BenefitsofPRS

• Testingefficiencyandsimplicity– Completed/Continuous

• Standardizationoftestmethods– Ongoing

• Reliabilityofperformancepredictionmodels– Complete

• Performancevolumetricrelationships– Ongoing

• SameprinciplesandmethodsbetweenmixdesignandPRS– Ongoing

ChallengeswithPRS

StandardizationofTestMethods

SpecimenPrepAASHTOR83

FULLSIZESPECIMEN SMALLSIZESPECIMEN

SpecimenPrepAASHTOPPXXX

DynamicModulusAASHTOT378

DynamicModulusAASHTOTPXXX

CyclicFatigueAASHTOTP107

CyclicFatigueAASHTOTPXXX

StressSweepRuttingAASHTOTPXXX

ReliabilityofPerformancePredictionModels

59asphalt mixtures,includingWMAand

RAPmixtures,from55pavementsections

FHWA-ALFSections

0

10

20

30

40

50

60

70

1.E+00 1.E+02 1.E+04 1.E+06

Dam

age

Area

(%)

No. of Cycles

ControlCRTRSBS

(a) FlexPAVE Prediction

0

20

40

60

80

100

1.E+02 1.E+03 1.E+04 1.E+05

Cra

ck A

rea

(%)

No. of Cycles

ControlCR-TBTerpolymerSBS-LG

Field Measurement(b)

0

5

10

15

0 3 6 9 12 15

Pre

dict

ed R

D fr

om S

-TS

S (m

m)

Measured RD (mm)

FHWA NCAT MIT-WMA MIT-RAP LOE

0

5

10

15

0 3 6 9 12 15

Pre

dict

ed R

D fr

om S

-TS

S (m

m)

Measured RD (mm)

NCAT MIT-WMA MIT-RAP LOE

BeforeCalibration

AfterCalibration

19

RutDepthPredictions

• Predictas-builtperformance– Withoutperformancetesting

• DatabasedevelopedatTFHRC• Expansionunderwayinshadowprojects

– Willuseplant-producedvariations• Agencyandcontractorguidanceforplanningpurposes

PerformanceVolumetricRelationships(PVR)

• Useoffundamentalteststocapturevariancebetweenas-designedandas-builtAQCs

• AsphaltMixturePerformanceTester(AMPT)usedinperformance-engineeredmixturedesign(PEMD)

• Performancevolumetricrelationshipsusedinconstruction

• Structuralresponsemodel(stressesandstrains)

FHWAPRSInitiative

• Useoffundamentalteststocapturevariancebetweenas-designedandas-builtAQCs

• AsphaltMixturePerformanceTester(AMPT)usedinperformance-engineeredmixturedesign(PEMD)

• Performancevolumetricrelationshipsusedinconstruction

• Structuralresponsemodel(stressesandstrains)

FHWAPRSInitiative

• Fundamental– Howmuchdistress?Howmuchlife?– Stressesandstrains– Materialproperties(i.e.,modulus)– Usewithstructuralresponsemodel– Manytemperature/loadingconditionsrepresented

• Index-Based– Go/no-go:correlation-based– Someengineeringproperties,someempirical

• Moretiedtoamaterialdatabase– Notusedwithstructuralresponsemodel(FlexPAVE)– Onlyafewtemperature/loadingconditionsrepresented

Performance-engineeredmixturedesign(balancedmixturedesign)

• Fundamental– Howmuchdistress?Howmuchlifegained/lost?– Stressesandstrains– Materialproperties(i.e.,modulus)– Usewithstructuralresponsemodel– Manyloadingconditionsrepresented

• Index-Based– Go/no-go:correlation-based– Someengineeringproperties,someempirical

• Moretiedtoamaterialdatabase– Notusedwithstructuralresponsemodel– Afewloadingconditionsrepresented

• Cost-efficientwaytoaccountforrelevantdistress!

Performance-engineeredmixturedesign(balancedmixturedesign)

FHWAPRS

• GraphicaluserinterfacessimilartoSameclimate,trafficinputs– Fewerunboundlayerinputsneeded

• AASHTOTP107resultsproventobecompatiblewithK1,K2,K3fatiguecoefficients

• AASHTOT378(|E*|)remainscriticalinput

AASHTOWare PavementME-FlexPAVETMCompatibility

• FlexMATTM – Excelspreadsheet– Analyzescyclicfatigue,|E*|,andSSRdata– Importfilesdirectly– Outputà FlexPAVETM

• FlexPAVETM – performancepredictiontool– PEMDthroughacceptance– Simulateas-designandas-builtperformance

FlexMATTM andFlexPAVETM Available

FlexMATTM

FlexPAVETM

PredictsPerformance!

PredictsPerformance!

Performancecriteriadeterminespavementlife!Compareas-designlifetotheas-builtpavement

lifeinPASSFlexTM toassignpayfactors!

• Time-temperaturesuperposition– Majorbenefit– Reducestestingtime/specimens– Enablesrobustnessofmodels

• Fundamentalpropertiesrequiredtodescribebehavioracrosswide-rangeofconditions

• Allowsfordirectincorporationofpavementstructureintopredictions

MaterialBehaviorAcrossAllLoadingConditions

• Time-temperaturesuperposition– Majorbenefit– Reducestestingtime– Enablesrobustnessofmodels

• Fundamentalpropertiesrequiredtodescribebehavioracrosswide-rangeofconditions

• Allowsfordirectincorporationofpavementstructureintopredictions

MaterialBehaviorAcrossAllLoadingConditions

FHWAShadowPRSProgram

• Howwouldprojecthavebeenaccepted,(andcontractorpaid),ifPRSwereused

• UnderstandwaysthatPRSmayimpactnormaltestingandacceptanceoperations

ObjectivesofShadowPRS

• DOTdeterminesproject(s)• DevelopsamplingplanwithFHWA,NCSt.,ARA– 10plant-producedsamples– Proficiencysample(1projectonly)– Mixdesignreplicationsample

• TrainingbeforeAMPTtestingbegins• Volumetrictestingasnormallydone• AMPTtestingwheneverDOThastime

HowWillThisAllWork?

ShadowPRSStatus

• MarylandSHA– Underway(10projects)• MaineDOT– Underway• MissouriDOT– Underway(3projects)• OntarioMOT– Underway• WesternFederalLands– 1st ProjectComplete

• Marketingofsuccessstories

• National/International– TRBAnnualMeeting–Discussionofissues,bestpractices,futureefforts

– 164members• 28DOTsrepresented

• Regional–User-ProducerGroups– StateAsphaltPavingAssoc.meetings

AMPTUsersGroup

AsphaltTechnologyGuidanceProgram(ATGP)

Long-Life Asphalt Pavement for the 21st Century

Office of Asset Management, Pavements, & Construction

ProgramFocusAreas

• ProvideSupporttoNationalInitiatives– IncreasedPavementDensity

– IncreasedRAP/RASUsage

– UnderstandingGTRTesting

– MixturePerformanceTestingandtheAMPT

– StoneMatrixAsphalt

– BinderPerformanceTesting

– Long-TermAging39

ProgramFocusAreas(2)

• EquipmentDevelopment&Refinement

– AsphaltMixturePerformanceTester(AMPT)• StandardizationofEquipment,TestMethods

– BinderPerformanceTesting

• DevelopmentofNewQAConceptsforHMA– Performance-Based/RelatedandRisk-BasedAcceptance

• AdvancedRapidTestTools– AIMS,CoreLok,CoreDry,Small-ScaleGeometry

40

41

SolutionstoAgencyNeeds

• Project-SpecificWorkplans–MaterialCharacterization

• HighRAP/RAS,GTR,SMA,PRS…

–MixDesignReplicationandTesting–MixProductionTesting–PerformancePrediction–TrainingandDemonstration

• Questions?• Contactinformation(PRSandShadow)

– RichardDuval– 202.493.3365– Richard.duval@dot.gov

• Contactinformation(AMPTandPRS)– DavidMensching– 202.366.1286– david.mensching@dot.gov

Thankyou!

• Pavementinventoryandconditions(NHS)• Objectivesandmeasures• Performancegapidentification• Lifecycleplanningandriskmanagementanalysis

• Financialplan• Investmentstrategies• Shorttermperformancemeasureskeytoinvestfundseffectivelyandmeetlong-termgoals!

• Performancepredictionleadstosmartplanning!

AssetManagementPlans

• Lowtemperaturesorfastloadingrate– Thermalcracking

• Intermediatetemperaturesandloadingrates– Fatiguecracking– Durabilitycracking– Thermalfatigue

• Hightemperaturesandslowloadingrates– Rutting– Increasedoxidativeaging

• Insufficientstructure– Rutting– Fatiguecracking

• Allinfluenceridequality

AsphaltPavementPerformance

PRSFramework

SamplingofMixtures/DatafromPavingProject

PerformanceTestsinAMPT

FlexMATTMExcel-BasedData Analysis

FlexPAVETMPavement

PerformanceAnalysis

PredictionofLife

ApplicationofPay

FactorsinPASSFlex™

Incentives/Disincentives

PerformanceMonitoring&Feedback

TestingEfficiencyandSimplicity

Small Specimen

|E*| Tests Fatigue Tests

Large Specimen

|E*| Tests

Fatigue Tests

TestingEfficiencyandSimplicity(2)

LargeSpecimen SmallSpecimen

SteelPutty Devcon 10110 Devcon 10240

Working Time 10 – 20min. 5min.

FunctionalCure 16hours 1hour

AmountofPutty(perspecimen) 100g 3g

• Addfailurecriterion• Simplificationoflanguage• AMPT-specific• Removalofspreadsheetderivation• Newstrainselectionguidance• Small-specimenappendix• Instructionalvideos(linksavailable)

AASHTOTP107Revisions

• Testingisconductedatmixdesignphase

• Runpredictionstoestablishas-designpavementlife

• Sameprinciplespresent– Predictionusingcyclicfatigueandshiftmodels

– Payfactorsassignedonalifedifference

SamePrinciplesandMethodsinDesignandPRS

• TransportationPooledFundStudy(TPF(5)-178)– Purchase,installationof29AMPTs– NHICourse(over80trainees)– Interlaboratory studyoneffectofairvoids– Nationalworkshop– Equipmentspecification,andothers!

• Teststandarddevelopment,improvement,andrevision

• Instructionalvideos,TechBriefs• PRSshadowimplementation(TFHRC-led)• PRSworkshops(2017,2018,2019)• MATTprojects/training• UserGroupsatTRBandregionalmeetings

AMPTImplementation

AMPTOverview

DynamicModulusTest

• MixtureStiffness• Rutting• FatigueCracking

StressStrain

s e00

lT

Tp

Timese

E*0

0=

Dynamic Modulus Phase Angle

TTf

p

l= (360)

DynamicModulusMasterCurve

Reduced Frequency, Hz

10,000,000

1,000,000

100,000

10,000

1,000

115°F

70°F

40°F

FIT

1.0E-06 1.0E-04 1.0E-02 1.0E+00 1.0E+02 1.0E+04 1.0E+06

E*min=4,259 psi

E*max=3,376,744 psi

R2= 0.9978Se/Sy= 0.038 3

2

1

0

-1

-2

-3Lo

g Sh

ift F

acto

r0 50 100 150

Temperature

E*,

psi

High Temperature: 0.4s pulse, 3.6s rest

20°C: 0.4s pulse, 1.6s rest

0.4s x 200 cycles for each loading block

0.4s x 200 cycles for each loading block

StressSweepRutting(SSR)Test

0.0%

0.5%

1.0%

1.5%

2.0%

0 200 400 600

Perm

anen

t Str

ain

Number of Cycles

S-TSS: TH

100 psi70 psi

130 psi

SSR:TH

0.0%

0.5%

1.0%

1.5%

2.0%

0 200 400 600

Perm

anen

t Str

ain

Number of Cycles

S-TSS: TL

TL 70 psi 100 psi 130 psi

SSR:20°C

• DraftprocedurereadyforconsiderationbyAASHTO

• FlexMATTM-Ruttingavailable– Singletabspreadsheet

• Confinedtesting(10psi)• 1daytocompleteallreplicates• Modelpredictspermanentdeformationatallloadingconditions!

SSRTest

• Fundamental,repeatedloadingtest• Directtension(pull-pull)• Small-specimentestingavailable(AASHTOTPxxx)

• AASHTOTP107– revisionsoutforballot!

• Materialbehavioracrossallpossibleloadingconditions!

AMPTCyclicFatigue

• Pavementpredictionsoftwarebuiltfrommodels

• Fieldvalidation– 59mixtures– 55differentpavementstructures

• Developlaboratory-to-fieldtransferfunctions

• Volumetrics haveaseatatthetable!

FieldValidationofAMPTCyclicFatigue

• AASHTOT378|E*|– Complete!• AASHTOTP107– Ruggednessandprecisionandbiasunderway

• Small-specimencyclicfatigue–Ruggednessandprecisionandbiasunderway

• Small-specimen|E*|– comingsoon

Ruggedness,Precision,andBias

InitialPVRDatabase

Relative notabsolutedistress

ApplicableforaparticularstructureandtrafficBUTwecangenerateacatalogwithFlexPAVETM

AnchorpointisstandardSuperpave• MinimumVMAforNMAS• 4%DesignAirVoids• 7%AirVoidsIn-PlaceDensity

• Cylindricalspecimens– AASHTOR83forfull-size– Draftprocedurereadyforsmall-size

• Equipmentrequired– Superpave gyratorycompactorandmolds– Coredrill(bitsdependonspecimensize)– Wetsaw– Waterbathorotherdevice(forGmb)– Engineeringsquare,pianowire

StandardSamplePreparation

PRSSoftware

AMPT+PerformancePrediction

PredictedRuttingPredictedCracking

ü Structure üClimateüTraffic

AMPTCyclicFatigueProcess

Preparation- Cylindricalspecimen- 100mmx130mm- Small-specimen:38mmx110mm

- Endplategluing,clampsystembeingexplored- 2-3daysformix

Testing- Dynamicmodulus

fingerprintforspecimenvariability

- Pull-pullfatiguetest- Strainlevelbasedon

TFHRCdatabase- Testtemperaturebasedonlocationofinterest- Loaduntilcrackforms

- 1-2daysformix

Analysis- AMPTautomatically

capturesdataforanalysis- CalculatedamageviaFlexMAT orFlexPAVE

- AssignmixturerankingsoruseFlexPAVE

- 1-2hoursformix

Aboutoneweekpermixture…worthitwhenconsideringthecostofprematurefailure?

• Standardsamplepreparation• AASHTOWare PavementMEcompatible• Ruggedness,precisionandbiasunderway

• FlexMATTM &FlexPAVETM available• Predictsperformance!• Materialbehavioracrossallpossibleloading/temperatureconditions!

AdvantagesofAMPTCyclicFatigue

FlexPAVETM SimulationsFHWA-ALFSections

This image cannot currently be displayed.

• Accept‘shadow’mixturesbasedontheperformanceengineeredmixdesign(PEMD)approach

• Collectvolumetric-basedacceptancequalitycharacteristics(AQCs)duringconstruction(PASSFlexTM)– Thesewouldbeusedtodeterminehypotheticalcontractorpay

TwoMajorTasksforDOT

• ProficiencyTesting– EnsurerepeatableresultswithseparatelaboratoryAMPT

– Onlydoneonfirstshadowproject• PEMDTesting

– Baselinefortheas-designedcondition– Neededindesignphaseofeachproject

• ProductionTestingwithAMPT(Shadowonly)– EstablishPVR

• ProductionTestingwithVolumetrics

MaterialTesting

• UnderstandingconceptofPRS– Understandingpavementfatigueandruttingusing

fundamentaltestprocedures– PavementperformanceasfunctionofAQCs– ConstructionAcceptance

• AMPTtraining– ARA,NCSU,&FHWAwillworkwithStateAgencyto

determinethebestsolutionfortraining.TheFHWA-MATTprovidesopportunitiesforDOTstolookovertheshoulderofitspersonnelwhentestingforperformance.

• PRSSoftwaretrainingandanalysissupport• PotentialforFHWAprojectfundingsupport• PotentialforMobileAsphaltTestingTrailersupport

WhatWillaDOTGetOutofShadowProjectParticipation?

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ProgramObjectives

• AdvancePerformance

• AdvanceQualityAssurance

• AdvanceInnovation

CourtesyofAntonPaar