concrete pavement design and sustainability - northwest pavement ??93 rigid pavement design ......

Download CONCRETE PAVEMENT DESIGN AND SUSTAINABILITY - Northwest Pavement  ??93 Rigid Pavement Design ... CONCRETE PAVEMENT DESIGN AND SUSTAINABILITY Jim

Post on 29-Mar-2018

242 views

Category:

Documents

20 download

Embed Size (px)

TRANSCRIPT

  • CONCRETEPAVEMENTDESIGN ANDSUSTAINABILITY

    2012NWPMACONFERENCEOctober23,2012

    Vancouver,WA

    JimPowell,P.E.ExecutiveDirector

    AmericanConcretePavementAssociation,NorthwestChapter

  • TheNewPavingReality

  • ConcretePavementSustainability

    Longevityisthehallmarkofconcrete pavements

    >50yearoldpavementscommon Benefitsbeyondlongevity

  • ConcretePavementLongevity

  • ConcretePavementLongevity

  • ConcretePavementLongevity

  • BenefitsofLongevity

    Lessfrequentreconstruction Lowerconsumptionofrawmaterials

    Cement,aggregates,steel LessCongestion

  • BenefitsofLongevity

    Reductioninpollutants Manufacturing,construction,congestion

    Infrequentconstructionzones Realeconomicbenefits

  • RawMaterialsSavings

    EquivalentSections 8

    HMAon12

    CSBC

    10

    PCCPon4

    CSBC

    FutureOverlays 2

    millandfillevery10 15years

    Savingsof2,200tons/lanemileover50years

  • SustainableBenefitsBeyond Longevity

  • SustainabilityandRoadways?

    ACPASpecialReport onGreenRoadways

    Emphasizeslongevity

    as theprimaryopportunity!!

  • Whatarewecurrentlyfocusingon?

    Sustainabilityprogramsandratingsystemshave emergedforpavements.

    GreenRoads(rateroadways,notanLCA) FHWASelfEvaluationTool(rating) FHWASustainablePavementsTWG ISIEnvision

    (rating)

    Relatetoproduction/constructionphases Littleisfocusedonthelongtermuseor

    operationalphaseofitslifecycle!

  • Whatshouldwebedoing?

    Clarification:Allthecommonlyadoptedsustainability

    strategiesareimportantandshouldbe embraced!

    though,itisusefultoknowwherewecanbemost impactful.

    RecentcomprehensiveLCAstudiesaregivingus cluesastowherethatis...

  • Whatshouldwebedoing?

    [CentredEnergetiquedelEcoledesMinesdeParis]

    Ecoprofileof

    differentlife

    cyclestagesof

    atypicalroad

  • Whatshouldwebedoing?

    FromthisLCAwesee: Overallimpactsfromusephasedwarfsimpactsfrom

    ALLotherphasesoftheroadwaylifecycle Fromenergyperspective

    constructionand

    maintenanceaccountsforlessthan2%oftheentire energyfootprint[EAPA2004]

    Therefore(asanexample): Justa23%

    improvementinthetruck/carportionof

    theecoprofilecouldoffsettheentireconstructionand maintenanceecoprofile!

  • Whatshouldwebedoing?

    [CentredEnergetiquedelEcoledesMinesdeParis]

  • Whatshouldwebedoing?

    Extraction,Production,Construction

    EndofLife

    Wheredoourconventional

    sustainabilitytoolsfitinthisecoprofile?

    RCA,RAP,Flyash,Slag,WarmMix?

    USEPHASE

    ECOPROFILE

  • Whatshouldwebedoing?

    Extraction,Production,Construction

    EndofLife

    USEPHASE

    SO

    ifwemakea30%

    improvementintheproductionenergyfootprint

    ECOPROFILE

    thatsmallsliverwouldbetheimpactontheentirelifecycleecoprofile!

  • Whatshouldwebedoing?

    Extraction,Production,Construction

    EndofLife

    USEPHASE

    However,whatifwecanfindawaytoreducetheusephaseportionby,say5%?

    ECOPROFILE

    Thisyellowareawouldrepresenttheoverallimpact

  • Whatshouldwebedoing?

    Whataretheseuse/operationalphaseimpacts?Vehiclefuelconsumptionrates

    Pavementrigidity Pavementsmoothness

    Pavementsurfacereflectivity(albedo) Urbanheatislandmitigation Lightingneed Globalcoolingpotential

  • VehicleFuelEconomy

    AreweFocusingontheRightThings?

  • VehicleFuelEconomy

    RigidSurfaceLowerDeflection

    LessLoss Indepthstudyby

    NationalResearchCouncil Canada

    Significantfuel consumptionreductions

    fortrucksonconcrete pavement(0.86.9%)

    Sweden,UTA,NCHRP, MIT

  • VehicleFuelEconomy

    USDOTdata UStruckfuelconsumption~39

    billiongallonsperyear Withjusta3%improvementonroughly50%of

    thenetwork,savingswouldamountto approx 585milliongallonsofdiesel/yr(13.5billionlbsCO2

    eq.and$2.3billion) Additionalsavingsfromlightervans,cars,etc.

  • VehicleFuelEconomy

    Smoothness

    smoothroadsarefuel efficientroads.

    Shouldspecify

    andconstructsmooth concretepavements

    FHWAreporteda4.5%

    improvementin fueleconomy(trucks)withsmoothness (IRI)improvingfrom152in/mileto

    76in/mile(00). OngoingworkaswellatMITandNCHRP. Appliesnotjusttonewpavements must

    maintainsmoothness.Pavementrenewal!

  • SurfaceReflectivity

    AreweFocusingontheRightThings?

  • SurfaceReflectivity

    Lighting

    EnhancedNighttime Visibility:

    Improvedpedestrianand vehiclesafety

    Reducedlighting& energyrequirement:

    Fewerfixtures/watts Upto33%reduction AASHTO

    40%lower

    Hugebudgetimpact!

  • UrbanHeatIslandMitigation: Urbanareasupto9Fwarmerdueto

    UHIresultingingreaterenergyuse andresultingpollution

    PCCPisaneffectivemitigation strategy

    lowercitytemperatures lowercoolingcosts reducesmogformation

    Pot.energysavings$2BinUS alone(LBNL08)

    SurfaceReflectivity

  • SurfaceReflectivity

    5th

    CAClimateChangeConference(LBNLandCEC)

  • SurfaceReflectivity

    Conceptisthatearthisnotaclosedsystem

    Reflectivematerialsonearthssurface(snow, ice,concrete)returnmoreofsunsenergy

    backintospace reducingtemperatures ThisamountstotheequivalentofCO2

    reduction(offset)

  • GlobalCooling

    Cities1%ofgloballandarea 60%cities=roofs/pavements Coolroofsandpavements(concrete)can

    increaseurbanalbedoby0.1,andinturn inducenegativeradiativeforcing.

    Ifimplementedin100largestcitiesin world,thiscanoffset44Gt

    ofemittedCO2

    ($1.1trillionat$25/ton) proposaltoUN considered.

  • PavementEngineering

    theartofmolding materialswedonot whollyunderstandinto

    shapeswecannot preciselyanalyzesoas

    towithstandforceswe cannotassessinsucha waythatthe

    communityatlargehas noreasontosuspect

    ourignorance.

  • ThicknessDesign

    Thenewpavementwillbebuiltinthefuture,onsubgrades oftennotyetexposedoraccessible,usingmaterialsnotyet manufacturedfromsourcesnotyetidentified,bya

    contractorwhosubmittedthesuccessful"lowdollar"bid, employingunidentifiedpersonnelandproceduresunder

    climaticconditionsthatarefrequentlylessthanideal. Measurewithamicrometer,markwithagreasepenciland

    cutwithanaxe

    wedesignto100th

    ofaninch,roundupto

    nearest

    andthencontractoroverbuildsthicknessand

    usesmaterialswithhigherthannecessarystrengthto ensurepay.

    Howmanyconcretepavementsfailbecauseofthickness?

  • MechanisticDesign

    Apurelyscientificapproach Reliesonmechanicsofstructuralbehaviorto

    loading Requiresknowledgeoffundamentalmaterial

    properties Requiresknowing(precisely)thegeometric

    propertiesofthestructure

  • EmpiricalDesign

    Basedonresultsofexperiments orexperience

    Requiresmanyobservationsto establishlinksbetweendesign variablesandperformance

    Doesnotrequireestablishinga scientificbasisforobserved

    relationships

  • TheAASH(T)ORoadTestIntroductiontotheWinPASDesignProcedure

  • AASHORoadTest

    Conceivedandsponsored bytheAmerican

    AssociationofState HighwayOfficialstostudy

    theperformanceof pavementstructuresof

    knownthicknessunder movingloadsofknown magnitudeandfrequency.

  • AASHORoadTest(19581960)

    ThirdLargeScaleRoadTest MarylandRoadTest(195051)

    RigidPavementsOnly

    WASHORoadTest(195254)FlexiblePavementsonly

    Includedbothconcreteandasphalt designs

    Includedawiderangeofaxleloadsand pavementcrosssections

  • TypicalAASHOLoopLayoutTestTangent=6,800

    ft368rigidsections

    468flexiblesections

  • Subgrade=ClaySoil

  • AASHOTestTraffic

    MaxSingleAxle

    MaxTandemAxle

  • PerformanceMetric

  • SomeAASHOResults

    Loop2

    1,114,000loadapplicationstoend

  • SomeAASHOResults

    Loop2

  • SomeAASHOResults

    Loop4

  • SomeAASHOResults

    Loop4

  • SomeAASHOResults

    Loop6

  • SomeAASHOResults

    Loop6

  • SomeAASHOResults Average ServiceabilityofSurvivingSections

  • LTTPJPCPSurvivalCurve

    http://www.fhwa.dot.gov/pavement/concrete/pubs/07019/chapt5.cfm

    FHWAHRT07019,AdvancedQualitySystems:GuidelinesforEstablishingand

    MaintainingConstructionQualityDatabases,2006

    http://www.fhwa.dot.gov/pavement/concrete/pubs/07019/chapt5.cfm

  • AASHORoadTestPerformance

    Theprimarymodeof

    concretepavement failureattheroadtest

    waslossofsupportin thepoorclaysoil.

    Allcrackingofconcrete

    pavementsattheAASHO roadtestwaspreceded

    bythepumpingof materialfrom

    underneaththeslab.Improveddesigns(dowel,subbase,geotex,etc.)havesolvedthis

    problem!

  • TheAASHTOPavementDesign Method

    IntroductiontotheWinPASDesignProcedure

  • AASHTODesignProcedures& Changes

    196162

    AASHOInterimGuidefortheDesignofRigidand

    FlexiblePavements1972

    AASHTOInterimGuidefortheDesignof

    PavementStructures

    Consolidate+update1981

    RevisedChapterIIIonPortlandCementConcrete

    PavementDesign Minorrevisions1986

    GuidefortheDesignofPavementStructures

    Majorrevisionstosubgradesupport;added overlays,reliability,LCCA,pavementmanagement

    1993

    RevisedOverlayDesignProcedures

    Addressed

    deficienciesin86overlaydesign;basisofWinPAS2010

    DARWinMETM

    Mechanisticprinciplesadded

  • Log(ESALs) Z * s + 7.35 * Lo

Recommended

View more >