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Balanced Mix (BMD) - apa-mi. · PDF fileBalanced Mix Design ... •Air voids not used...

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  • BalancedMixDesign(BMD)

    ASPHALT PAVEMENT ASSOCIAT ION OF MICHIGAN (APAM)2017 ASPHALT PAVING CONFERENCE

    SHANE BUCHANANOLDCASTLE MATERIALS

  • DiscussionItems

    NeedforBalancedMixDesign PerformanceTestingDiscussion BalancedMixDesignTaskForceActivities AgencyPracticesRelatedtoBalancedMixDesign

    FutureWork

    AMAP|2017

  • Asphaltmixdesignusingperformancetestsonappropriatelyconditionedspecimensthataddressmultiplemodesofdistresstakingintoconsiderationmixaging,traffic,climateandlocationwithinthepavementstructure.

    Basically,itconsistsofdesigningthemixforanintendedapplicationandservicerequirement(e.g.,usetherighttoolforthejob!)

    BalancedMixDesignDefinition

    AMAP|2017

  • NeedforBalancedMixDesign

  • Problems: Relyingonvolumetricsalonetoprovide

    performance Drymixesexistinsome(notall)areas

    Solutions: Recognizeperformanceissuesrelatedtodrymixes

    insomeareas.(Note:Manyperformanceissuesarecausedbyfactorsoutsidethemixdesign)

    Increaseunderstanding ofthefactorswhichdrivemixperformance

    Designforperformanceandnotjusttothespec. Startthinkingoutsideoflongheldrulesand

    constraints Innovate!

    WhytheNeedforaNewMixDesignApproach?

    2017APAMPavingConference

  • WhatTypeDistressIsOccurring?

    OldcastleSurveyQuestion:Withinthepast5years,whattypeofmixperformancerelateddistresshasbeenmostevidentinyourmixes?

    ~40companiesrespondingfrom~30states

    OldcastleSurveyQuestion:Withinthepast5years,whattypeofmixperformancerelateddistresshasbeenmostevidentinyourmixes?

    ~40companiesrespondingfrom~30states

    2017APAMPavingConference

  • Eachday,approximately1.4MilliontonsofHMAareproducedintheU.S.(MFproductionbasis) [email protected]

    DistancefromNewYorktoLasVegas

    StepsMustbeTakenNow TowardsSolutions

    Longtermresearchiscertainlyneeded,butwemusttakestepsNOW towardsasolution

    2017APAMPavingConference

  • Largelyrecipedriven Aggregatesandgrading Volumetrics(Va,VMA,VFA,D/A,etc.) Bindergradeand/orminimum% RAPand/orRAS WMA

    Whilethismay work,thereareproblems Whathappenswhentherecipefails?

    Specificationshavebecomeconvolutedandconfounded Existingspecifieditemscompeteagainsteachother Newrequirementsgetaddedandnothinggetsremoved SpecBookCreep

    Innovationhasbecomestifledwithourknowledgeoutpacingspecifications

    MixDesignSpecifications

    2017APAMPavingConference

  • State GyrationLevel1

    NewMexico 75,100,125NewYork 50,75,100

    NorthCarolina 50,65,75,100Ohio 65Oklahoma 6422(50),7028(60),and7628(80)Oregon 65,80,100

    Pennsylvania 50,75,100RhodeIsland 50Tennessee 65or75MarshallTexas 50Utah 50,75,100,125Vermont 50,65,80Virginia 65

    Washington 50,75,100,125WestVirginia 50,65,80,100

    State GyrationLevel1

    Alabama 60Arkansas 50,75,100,125Colorado 75,100Connecticut 75,100

    Florida 50,65,75,100

    Idaho 50,75,100,125Iowa 50,60,65,68,76,86,96,109,126Kansas 75,100

    Kentucky 50,75,100Maine 50,75Massachusetts 50,75,100Michigan 45,50,76,86,96,109,126

    Minnesota 40,60,90,100Mississippi 50,65,85

    Missouri 50,75,80,100,125Montana 75Nebraska 40,65,95

    Nevada UseHveemNewHampshire 50,75NewJersey 50,75

    Ndesignvarieswidelyw/levelsbeingreducedwiththeintentofgainingmorebinder

    Problem:Lowergyrationsdonotnecessarilyequatetomorebinder

    AgenciesareSearchingforSolutions:Ndesign

    AsofMarch2015

    2017APAMPavingConference

    SouthCarolina:50,75,100

  • EnhancingtheDurabilityofAsphaltPavements

    VolumeofEffectiveBinder(Vbe)istheprimarymixturedesignfactoraffectingbothdurabilityandfatiguecrackingresistance. Vbe=VMA AirVoids

    Anumberofstatehighwayagencieshavedecreasedthedesigngyrationlevelsinanattempttoincreaseeffectivebindercontents.However,decreasingthedesigngyrationsmaynotalwaysproducemixtureswithhigherVbe.

    2017APAMPavingConference

  • Superpavesystemisbecomingunrecognizablewithspecificationschangingrapidlyasagenciessearchforwaystoimprovedurability

    Establishingtruecauseandeffectisimpossible

    AgenciesAreSearchingforSolutions:SpecChanges

    SurveyQuestion:WhichofthefollowingspecificationchangeshasyourDOTimplementedinthelast5years?

    SurveyQuestion:WhichofthefollowingspecificationchangeshasyourDOTimplementedinthelast5years?

    2017APAMPavingConference

  • MichiganNdesign

    2017APAMPavingConference

  • MichiganAirVoidRegression

    2017APAMPavingConference

  • Mix3:

    VMAMin.=13% VFA(E10)=65to78%

    EnsureSpecificationItemsAgree

    2017APAMPavingConference

    VMAMinimum,% 13UpperVFA,% 78LowerVFA,% 65EffectiveUpperVa,% 4.55EffectiveLowerVa,% 2.86EffectiveUpperVbe,% 10.14EffectiveLowerVbe,% 8.45

  • Mix5:

    VMAMin.=15% VFA(E10)=73to76%

    EnsureSpecificationItemsAgree

    2017APAMPavingConference

    VMAMinimum,% 15UpperVFA,% 76LowerVFA,% 73EffectiveUpperVa,% 4.05EffectiveLowerVa,% 3.6EffectiveUpperVbe,% 11.4EffectiveLowerVbe,% 10.95

  • 1890BarberAsphaltPavingCompanyAsphaltcement12to15%/Sand70to83%/Pulverizedcarboniteoflime5to15%

    1905

    CliffordRichardson,NewYorkTestingCompanySurfacesandmix:100%passingNo.10,15%passingNo.200,9to14%asphaltAsphalticconcreteforlowerlayers,VMAterminologyused,2.2%moreVMAthancurrentdaymixesor~0.9%higherbindercontent

    1920s

    HubbardFieldMethod(CharlesHubbardandFrederickField)Sandasphaltdesign30blow,6diameterwithcompressiontest(performance)asphalticconcretedesign(ModifiedHFMethod)

    1927

    FrancisHveem(Caltrans)Surfaceareafactorsusedtodeterminebindercontent;HveemstabilometerandcohesionmeterusedAirvoidsnotusedinitially,mixesgenerallydrierrelativetoothers,fatiguecrackinganissue

    1943

    BruceMarshall,MississippiHighwayDepartmentRefinedHubbardFieldmethod,standardcompactionenergywithdrophammerInitially,onlyusedairvoidsandVFA,VMAaddedin1962;stabilityandflowutilized

    1993

    Superpave Level1(volumetric) Level2and3(performancebased,butnever implemented)

    HistoryofMixDesign

    http://asphaltmagazine.com/historyofasphaltmixdesigninnorthamericapart2/

    BINDER

    CONTENT

    LOWER

    Stability

    Stability+Durability

    Stability+Durability

    2017APAMPavingConference

  • Designandoptimumbindercontentareoftenusedinterchangeably However,theymeantwodifferentthings

    Therecanbemanydesignbindercontentsforamix,butonlyonetrulyoptimum

    Optimumindicatesthebestbindercontentbasedonintendedapplication,performancerequirements/needs,andultimatelyeconomics

    Goalistogetascloseaspossibletothetrueoptimum forthemix

    BinderContent Designvs.Optimum(Thereisadifference!)

    2017APAMPavingConference

  • PerformanceTestingofAsphaltMixes

  • StabilityTesting

  • Evaluatemixstabilitywithoneofseveralavailableruttingtools. Hamburg,APA,AMPTFlowNumber,etc. Failurecriteria

    Basedonbestavailableresearch(local,regional,ornational) Functionoftraffic(e.g.,low,medium,high)and/ormixenduseapplications

    StabilityEvaluation

    2017APAMPavingConference

  • Durability/CrackingTesting

  • Durability/crackingevaluationissubstantiallymorecomplicatedthanstability Whatisthemodeofdistress? Whatistheagingcondition?

    Crackingpredictionisaknownweaklinkinperformancetesting Nogeneralconsensusonthebesttest(s)

    ortheappropriatefailurethreshold

    GOALS MATCHTHETESTTOTHEDISTRESS SETAPPROPRIATEFAILURETHRESHOLDS

    Durability/CrackingEvaluation

    2017APAMPavingConference

  • LaboratoryCrackingTests(From:ResearchReportNo.FHWAICT15017)

    AMAP|2017

  • MatchtheTesttotheDistress

    From:LouayMohammad,LTRC

    DiscShapedCompactTension

    2017APAMPavingConference

  • CrackingTests:StrainandCyclesIllustration

    2017APAMPavingConference

  • WhatistheBestCrackingTest?ItDepends!

    NCHRP957:ExperimentalDesignforFieldValidationofLaboratoryTeststoAssessCrackingResistanceofAsphaltMixtures

    Note:SCBILisnowIFITAMAP|2017

  • UseofPerformanceTestinginDesign Illinois

    From:ImadAlQadi,UniversityofIllinois AMAP|2017

  • UseofPerformanceTestinginDesignWisconsin

    From:Erv.Dukatz,MathyConstruction,TRB2015 AMAP|2017

  • Performancespacediagramsshowtheperformanceofamixrelatedtomultipletests

    Allowsthemixdesignertovisualizethemixperformanceandhowtoengineerthemixtoprovidethedesiredperformance

    UsingPerformanceResultstoOptimizePerformance

    AMAP|2017

  • BalancedMixDesignTaskForce DevelopmentandWork

  • AttherequestoftheNationalPavementImplementationExecutiveTaskGroup(PIETG) aBalancedMixDesignTaskForceformedattheSeptember2015FHWAMixtureandConstructionETGmeeting

    ThePIETGisfocusedonthestrategicprogramlevelchallengesandopportunitiesinthedeploymentofpavementtechnologies.

    Focusareasinclude:

    PavementDesignandAnalysis;

    PavementMaterialsandQualityAssurance;

    PavementSurfaceCharacteristics;

    ConstructionTechnology;

    PavementSustainability;

    TechnicalCapacity;and

    FieldSupport/TechnicalAssistance.

    PavementImplementationExecutiveTaskGroup(PIETG)

    AMAP|2017

  • AMAP|2017

    JohnBukowski Materials TeamLeaderChristopherWagner PavmentandMaterials Tech.Srvs.TeamLeaderGinaAhlstrom PavementDesignandAnalysis TeamLeaderJeffWithee PavementMaterials EngineerMarkSwanlund InfrastructureR&DProgramCoordinatorBryanCawley ConstructionMgmt.TeamLeaderStephenGaj AssetMgmt.TeamLeaderHari Kalla Director,OfficeofAssetMgmt.,Pavement&Construction

    MikeAcott President NAPAAudreyCopeland VP,Engineeering,Tech.andResearch NAPA(attendee)GeraldVoigt President/CEO ACPALeifWathne VP,HighwaysandFederal Affairs ACPA(alternate)JimDuit President DuitConstruc

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