道路工程材料教学课件Road Engineering Materials CH2

RoadEngineeringMaterials

道路工程材料CollegeofAutomobileandTrafficEngineering汽车与交通学院QingdaoTechnologicalUniversity青岛理工大学Ch2Aggregates2.1TypesofAggregates2.2PropertiesofAggregates2.3MixdesignofaggregatesWhatisAggregates?Aggregatesisarocklikematerialofvarioussizesandshapes,usedinthemanufactureofPortlandcementconcrete,bituminousconcrete,plaster,grout,filterbeds,railroadballast,basecourse,foundationfill,subgrade,andsoon.2.1TypesofAggregatesCrushedstone碎石Sand砂Gravel砾石、卵石Crushedstone碎石Crushedstone碎石Sand砂Gravel砾石Gravel砾石TypesofAggregatesAggregatescanbedividedintoseveraltypes

BasedonsourceBasedonmethodofmanufactureBasedonsizeBasedondensity2.1.1BasedonsourceormethodofmanufactureNaturalaggregatesNaturalsandisformedfromweatheringanddecompositionofalltypesofrocks,themostabundantmineralconstituentbeingquartz.ManufacturedaggregatesManufacturedsandisproducedbycrushingstone,gravel,orair-cooledblast-furnaceslag,andischaracterizedbysharpandangularparticles.2.1.2BasedonsizeBasedonthemaximumsizeofparticlesinasample,aggregatesaredividedintotwogroups:FineaggregateItreferstotheaggregatewhosediameterislessthan4.75mm.CoarseaggregateItreferstotheaggregatelargerthan4.75mmBasedonsizeAggregatesbasedonsizeMaterialsParticlesize(mm)Fineaggregatesand0.075-4.75Coarseaggregategravel≥4.75CrushedstoneManufacturedaggregatecementconcrete沥青混合料的划分粗集料指粒径大于2.36mm的碎石、破碎砾石、筛选砾石及矿渣等。细集料指小于于2.36mm的天然砂、人工砂（机制砂）及石屑等。矿粉mineraldust;mineralfines;filler指由石灰岩或者岩浆岩等憎水性碱性石料经磨细加工而得到的，在混合料中起填充作用的，以碳酸钙为主要成分的矿物质粉末，也称填料。2.1.3BasedondensityBasedonspecificgravityordensitymeasuredinbulk,aggregateisdividedintothreetypes:LightweightaggregateNormal-weightaggregateHeavyweightaggregateBasedondensityBasedondensityBulkdensitykg/m3LightweightFineaggregate≤1120Coarseaggregate≤880Normal-weight1520-1680Heavyweight≥1680堆积密度，指单位体积（包含物质颗粒固体及其开口、闭口孔隙体积及颗粒间空隙体积）的物质颗粒质量，分松散堆积密度和振实堆积密度。LightweightaggregateLightweightaggregateMaterialsNaturalLightweightaggregatePumice['pʌmis]浮石Scoria['skɔ:riə]矿渣Tuff凝灰岩ManufacturedLightweightaggregateBlast-furnaceslagShale页岩Slate板岩Flyash粉煤灰Lightweightaggregatesareusedinthemanufactureoflightweightconcreteandlightweightmasonryblocks.Pumice（轻石，浮石）Tuff（凝灰岩）凝灰岩Shale页岩Slate板岩Flyash粉煤灰Flyash粉煤灰Normal-weightaggregateNormal-weightaggregatesarecommonlyusedinthemanufactureofnormal-weightconcrete,asphaltconcrete,androadsub-base.CrushedstoneGravelOrdinarysandHeavyweightaggregateHeavyweightaggregateisusedprimarilyinthemanufactureofheavyweightconcrete.MaterialsMineralOre(limonite褐铁矿,hematite赤铁矿,magnetite磁铁矿)Barite(BaSO4)重晶石aggregateTypeAverageSpecificGravityAveragebulkdensity(dry)kg/m3Granite花岗岩GravelLimestonePerlite

珍珠岩Pumice浮石Quartzite石英岩Scoria矿渣Expandedshale

Sawdust锯屑Expandedvermiculite蛭石ExpandedperliteSandBarite重晶石Sandstone砂岩Basalt玄武岩Magnetite磁铁矿Hematite赤铁矿Normalweight,mineralNormalweightNormalweight,mineralLightweight,naturalLightweight,naturalNormalweight,mineralLightweight,naturalLightweight,manufacturedLightweight,organicLightweight,manufacturedLightweight,manufacturedNormalweightHeavyweightNormalweight,mineralNormalweight,mineralHeavyweightHeavyweight2.652.702.652.500.752.690.751.000.500.200.752.604.502.552.854.505.001600-17601600-16801520-17608001052001650-176024001440-160024003040Aggregatetypesandspecificgravity2.2PropertiesofAggregatesPhysicalpropertiesSpecificGravityandBulkDensityMoistureContentPorosityandVoidsGradationandFinenessmodulusMechanicalpropertiesModulusofelasticityandStrengthChemicalproperties2.2.1SpecificGravitySpecificGravity——isdefinedastheratioofthemassofaunitvolumeofamaterial-ataspecifictemperature–tothemassofthesamevolumeofgas-freedistilledwateratthattemperature.2.2.2MoisturecontentBasedonthemoisturelevel,aggregatesaredividedintofourstatesOvendry(OD)Airdry(AD)Saturatedsurfacedry(SSD)Wet

MoisturecontentVeryimportantasitinfluencesthew/c；SSDstateismostoftenusedasareference,althoughitismoredifficulttoobtainthanODstate;Absorptionisveryimportant;Mostnaturalaggregateshaveanabsorptioncapacityof1to2percent;Effectiveabsorptionversussurfacemoisture.FormulaSurfacemoistureSurfacemoistureWhere,SM----Surfacemoisture;MC----Moisturecontent;AC----Absorptioncapacity.2.2.3BulkspecificgravityBulkspecificgravity

----istheratiooftheweightinairofaunitvolumeofapermeablematerial–whichincludesbothpermeableandimpermeablepores,ataspecifictemperature–totheweightinairofanequalvolumeofgas-freedistilledwater.2.2.4ApparentspecificgravityApparentspecificgravity—istheratiooftheweightinairofaunitvolumeoftheimpermeableportionofthematerial–ataspecifictemperature–totheweightinairofanequalvolumeofgas-freedistilledwateratthattemperature.2.2.5PorosityPorosity----isdefinedastheratioofthevolumeofporesinaparticletoitstotalvolume(solidvolumeplusthevolumeofpores)PorositysolidCloseporesOpenporesMass

Volume2.2.6VoidVoid----representtheamountofairspacebetweentheaggregateparticles.Voidcontent----thetotalvolumeminusthesolidvolumeofparticles.Where,SG----specificgravity;W-----thedensityofwater;B-----bulkdensity.VoidsolidOpenporesCloseporesVolumeMass

SolidVoidsVariationinthevolumeofvoidsforvarioussand-gravelmixturesPercentageofvoidsPercentageofsandinmixedaggregates2.2.7Bulkdensity/Loosedensity

堆积密度/松散密度Bulkdensity----isthemassofaggregateperunitbulkvolume.Unit:kg/m3next2.2.8Gradation级配Gradation----referstotheproportions-bymass-ofaggregateparticlesdistributedinspecialparticle-sizeranges.TypesofGradationDense-gradedaggregate----isanaggregatethathasaparticle-sizedistributionthatresultsintheleastvoidsorlowestvoidcontent.Open-gradedaggregate----isanaggregatethathasaparticle-sizedistributionthatresultsinrelativelylargevoidsorvoidcontent.Sieve[siv]筛子SieveAnalysis筛分CoarseaggregateSquareopening（mm）756337.531.526.519169.54.75Roundopening（mm）80634031.5252016105FineaggregateSquareopening（mm）4.752.361.180.60.30.15Roundopening（mm）52.51.250.630.3150.16Parametersofgradation(1)Singleremainder分计筛余(2)Accumulativeremainder累计筛余(3)Passingpercentage通过百分率(1)SingleremainderSingleremainder

----Arepresentativesampleoftheaggregateispassedthroughaseriesofsievesandtheweightretainedineachsieveexpressedasapercentageofthesampleweight.Where,αi----Singleremainder(%);mi----Theweightretainedineachsieve;m----Thesampleweight.(2)AccumulativeremainderAccumulativeremainder----iscalculatedthroughaddingthevaluesofthepercentagescoarserthaneachfullsieveintheset.Where,βi----Accumulativeremainder(%);αi----Singleremainder(%).TheRelationshipofAccumulativeRemainderandSingleRemainderonaSieveOpeningsize(mm)Singleremainder(%)Accumulativeremainder(%)4.75a12.36a21.18a30.6a40.3a50.15a6(3)PassingPercentagePassingPercentage

----theratiooftheweightpassingeachsievetothesampleweight.Where,pi----PassingPercentage

(%);βi----Accumulativeremainder(%).PassingPercentageofdifferentopeningsizeOpeningsize(mm)Singleremainder(%)Accumulativeremainder(%)PassingPercentage(%)4.75a1β1100-β12.36a2β2100–β21.18a3β3100–β30.6a4β4100–β40.3a5β5100–β50.15a6β6100–β6Example1——GradationRegionnext2.2.9FinenessModulus

细度模数FinenessModulus----isafactortoevaluatethedegreeofcoarsenessoftheaggregate.如果有＞4.75mm的，用下公式，否则去掉β1的两项Where,μf----FinenessModulus;βi----Accumulativeremainder(%).FinenessModulusSandisseparatedintothreetypesbasedontheFinenessModulus:Coarsesand

μf=3.7—3.1;Mediansand

μf=3.0—2.3;Finesand

μf=2.2—1.6.next2.2.10Modulusofelasticity

弹性模量Modulusofelasticity(Young’smodulus)----istheratioofstresstothecorrespondingstrainbelowtheproportionallimit.Atagivenstresslevel,amaterialwithahighermodulusdeformslessthanamaterialwithalowermodulus.Granite14–48GPaSandstone7–35GPa-Mechanicalproperties-2.2.11Uniaxialcompressionstrength

单轴抗压强度Uniaxialcompressionstrength——theultimatestrengthatfailureundertheuniaxialcompressionofthestandardsaturatedaggregate.单轴抗压强度——石料标准试件吸水饱和后，在单向受压状态下，破坏时的极限强度。Uniaxialcompressionstrength

单轴抗压强度JTJ054T0212-94公路工程石料试验规程50mm×50mm×50mmSaturatedbyabsorptionApplyuniaxialcompressionuntilultimatefailureUniaxialcompressionstrengthWhere,fSC----Uniaxialcompressionstrength;Fmax----loadatultimatefailure;A0----sectionareaofthetestingmaterial.next2.2.12Aggregatecrushingvalue

压碎值Aggregatecrushingvalue——themeasureofresistingcrushedofaggregateattheincreasingload.压碎值——用于衡量石料在逐渐增加的荷载下抵抗压碎的能力。

Aggregatecrushingvalue

压碎值Testingmethod(JTJ058T0316-94)Particlesizeis12–16mm;Volumeofgraduateis1767cm3;Puttheaggregateinsidebythreelayers;Tamping25timesforeachlayer;Appliedloadto400KNin10minutes;Themassofaggregatelessthan3mmismeasured.Aggregatecrushingvalue

压碎值AggregatecrushingvalueWhere,Cru----Aggregatecrushingvalue(%);m1----Themassofaggregatelessthan3mmaftercrushing;（g）m----Themassofthesample.（g）2.2.13Abrasionvalue

磨耗值Abrasion----isthemechanicalwearingandscrapingofrocksurfacesbyfrictionorimpactorboth.LosAngelesAbrasionTestWhere,Qab----Abrasionofaggregate(%);m1----Massofaggregategreaterthan2mmaftertesting;m----Thedriedmassofthesample.LosAngelesAbrasionTest

洛杉矶磨耗试验粗集料骨架间隙率：4.75mm以上粗集料在捣实状态下颗粒空间体积的百分含量。用于确定混合料中细集料和结合料的数量，评价粗集料的骨架结构。细集料的棱角性：对沥青混合料抗流动变形能力以及水泥混凝土的和易性十分显著。间隙率法流动时间法粗集料的针片状颗粒含量水泥混凝土-规准仪法；沥青混合料-卡尺法含泥量（细集料）和泥块含量（粗集料）其降低水泥水化反应速度，削弱集料和沥青之间的黏结能力。2.3MixdesignofaggregatesTheoryofgradationMixproportioningdesignmethodofaggregateGradingcurve级配曲线级配理论矿质混合料的组成设计2.3.1Gradingcurve级配曲线Continuousgradation连续级配----particle-sizedistributionofanaggregateiscontinuous.Gapgradation间断级配----oneormoreintermediatesizesofanaggregatearemissing.连续级配是某一矿质混合料在标准筛孔的套筛中筛分时，所得级配曲线平顺圆滑，具有连续不间断的性质，相邻粒径间有一定的比例关系（按质量计）。Gradingcurve级配曲线Sievesize(mm)ContinuousgradationcurveGapgradationcurvePassingpercentage(%)2.3.2Theoryofgradation级配理论

TheoryofmaximumdensitycurveTheoryofparticleinterference最大密度曲线理论(Fuller)粒子干涉理论(Weymouth)根据C.A.G魏矛斯（Weymouth）的研究结果，为达到最大密度，前一级颗粒之间的空隙，应由次一级颗粒所填充；所余空隙又由再次一级小颗粒所填充，但填充空隙的颗粒粒径不得大于其间隙之距离，否则大小颗粒粒子之间势必发生干涉现象，使空隙率增大。

Theoryofmaximumdensitycurve

最大密度曲线理论

Gradationhasaprofoundeffectonmaterialperformance.Butwhatisthebestgradation?Thebestgradationisonethatproducesthemaximumdensity.Thiswouldinvolveaparticlearrangementwheresmallerparticlesarepackedbetweenthelargerparticles,whichreducesthevoidspacebetweenparticles.

MaximumdensitygradationwasdevelopedbyFullerandThompsonin1907.EquationofmaximumdensitycurveBasedonthetheoryofmaximumdensity,itcanbeexpressedmathematicallywhere:p----%finerthanthesieve(percentpassing); d----aggregatesizebeingconsidered;

k----aconstant.Percentpassingp(%)Particlesizesd(mm)p-d

curvePercentpassingp(%)Particlesizeslgd(mm)p-lgdcurveEquationsofmaximumdensitycurvewhere:k----aconstant;D----maximumaggregatesizetobeused;

p----%finerthanthesieve(percentpassing); d----aggregatesizebeingconsidered.Equationofnpowermaximumdensitycurve最大密度曲线n幂公式where:p=%finerthanthesieve d=aggregatesizebeingconsidered D=maximumaggregatesizetobeused n=parameterwhichadjustscurveforfinenessorcoarseness(formaximumparticledensityn≈0.5accordingtoFullerandThompson)Particlesizeslgd(mm)Percentpassing(%)npowermaximumdensitycurven幂最大密度曲线OrderNRatioofparticlesizesD/2N-1Particlesizesd(mm)Percentpassing(%)n=0.5n=0.3n=0.7PercentpassingofmaximumdensitycurveandgradationregioncurvePlotofgradationregioncurve

级配范围曲线的绘制TheoreticalgradationregioncurveSievesizesasabscissa(lgd)Percentpassingasordinate(p)gradationregionn=0.3~0.7Gradationregioncurve

级配范围曲线GradationregioncurvePassingpercentage(%)Sievesizes(mm)2.3.3Mixdesignofaggregate矿质混合料的组成设计GraphicalmethodTrialanderrormethod图解法试算法Graphicalmethod图解法BalancedareamethodUsealinereplacingthegradationcurve;MaketheareabetweentheleftsideandrightsideequalGraphicalmethod(1)Plotmethodofgradationcurvecoordinates

级配曲线坐标图的绘制方法(2)Methodofdeterminingaggregatesproportion

各种集料用量的确定方法Percentpassing(%)Particlesizes(mm)(1)Plotmethodofgradationcurvecoordinates级配曲线坐标图的绘制方法p–lgdcurvePercentpassing(%)Particlesizes(mm)p–(d/D)ncurvePlotmethodofgradationcurvecoordinatesPlotmethodDrawarectangle:Take10cmforordinate,Take15cmforabscissa;Connectdiagonalasgradationmedian;Findthesievesizesbypercentpassing.PlotmethodofgradationcurvecoordinatesSievesizes(mm)16.013.29.54.752.361.180.60.30.150.075Gradationregion(mm)10095-10070-8848-6836-5324-4118-3012-228-164-8Gradationmedian(mm)10098795745332417126Table1Gradationregionofaggregatesusedinasphaltconcrete(GBJ92-93)Percentpassing(%)Sievesize(mm)gradationmedianPlotmethodofgradationcurvecoordinates(2)Methodofdeterminingaggregatesproportion

各种集料用量的确定方法Therearethreesituations:OverlapbetweentwoadjacentgradationcurvesConterminousbetweentwoadjacentgradationcurvesDeviationbetweentwoadjacentgradationcurvesPercentpassing(%)Sievesize(mm)Assignment1UsegraphicalmethodtodesigntheMixproportionoftheaggregates.Table1GradationofaggregatesmaterialsSieveopeningsizemm16.013.29.54.752.361.180.60.30.150.075Passingpercentage%Crushstone(A)10093170Stonescraps(B)1001001008414840Sand(C)10010010010092824221114Stonepowder(D)1001001001001001001001009687Table2Requiredgradationregionandmedian

规定的级配范围与中值GradationSievesize（mm）16.013.29.54.752.361.180.60.30.150.075Passingpercentage(%)Gradationregion10095-10070-8848-6836-5324-4118-3012-228-164-8Gradationmedian10098795845332417126Gradationregionofaggregatesusedinasphaltconcrete(GBJ92-93)(1)Plotgradationcoordinates绘制级配坐标Take10cmasordinate;Take15cmasabscissa;Marktheordinatewithpercentpassing.(2)Determinetheplaceofsievesizeonabscissa

确定各筛孔在横坐标上的位置ConnectdiagonalOO’torepresentgradationmedian;Accordingtotherequiredgradationmedian(percentpassing),findsievesizeonabscissa.(3)Plotgradationcurvesforeachaggregate.

绘制各种集料的级配曲线Percentpassing(%)Sievesize(mm)gradationmedianPlotmethodofgradationcurvecoordinatesPercentpassin