道路工程材料教學(xué)課件Road Engineering Materials CH2

RoadEngineeringMaterials

道路工程材料CollegeofAutomobileandTrafficEngineering汽車與交通學(xué)院QingdaoTechnologicalUniversity青島理工大學(xué)Ch2Aggregates2.1TypesofAggregates2.2PropertiesofAggregates2.3MixdesignofaggregatesWhatisAggregates?Aggregatesisarocklikematerialofvarioussizesandshapes,usedinthemanufactureofPortlandcementconcrete,bituminousconcrete,plaster,grout,filterbeds,railroadballast,basecourse,foundationfill,subgrade,andsoon.2.1TypesofAggregatesCrushedstone碎石Sand砂Gravel礫石、卵石Crushedstone碎石Crushedstone碎石Sand砂Gravel礫石Gravel礫石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瀝青混合料的劃分粗集料指粒徑大于2.36mm的碎石、破碎礫石、篩選礫石及礦渣等。細(xì)集料指小于于2.36mm的天然砂、人工砂（機(jī)制砂）及石屑等。礦粉mineraldust;mineralfines;filler指由石灰?guī)r或者巖漿巖等憎水性堿性石料經(jīng)磨細(xì)加工而得到的，在混合料中起填充作用的，以碳酸鈣為主要成分的礦物質(zhì)粉末，也稱填料。2.1.3BasedondensityBasedonspecificgravityordensitymeasuredinbulk,aggregateisdividedintothreetypes:LightweightaggregateNormal-weightaggregateHeavyweightaggregateBasedondensityBasedondensityBulkdensitykg/m3LightweightFineaggregate≤1120Coarseaggregate≤880Normal-weight1520-1680Heavyweight≥1680堆積密度，指單位體積（包含物質(zhì)顆粒固體及其開口、閉口孔隙體積及顆粒間空隙體積）的物質(zhì)顆粒質(zhì)量，分松散堆積密度和振實(shí)堆積密度。LightweightaggregateLightweightaggregateMaterialsNaturalLightweightaggregatePumice['p?mis]浮石Scoria['sk?:ri?]礦渣Tuff凝灰?guī)rManufacturedLightweightaggregateBlast-furnaceslagShale頁巖Slate板巖Flyash粉煤灰Lightweightaggregatesareusedinthemanufactureoflightweightconcreteandlightweightmasonryblocks.Pumice（輕石，浮石）Tuff（凝灰?guī)r）凝灰?guī)rShale頁巖Slate板巖Flyash粉煤灰Flyash粉煤灰Normal-weightaggregateNormal-weightaggregatesarecommonlyusedinthemanufactureofnormal-weightconcrete,asphaltconcrete,androadsub-base.CrushedstoneGravelOrdinarysandHeavyweightaggregateHeavyweightaggregateisusedprimarilyinthemanufactureofheavyweightconcrete.MaterialsMineralOre(limonite褐鐵礦,hematite赤鐵礦,magnetite磁鐵礦)Barite(BaSO4)重晶石aggregateTypeAverageSpecificGravityAveragebulkdensity(dry)kg/m3Granite花崗巖GravelLimestonePerlite

珍珠巖Pumice浮石Quartzite石英巖Scoria礦渣Expandedshale

Sawdust鋸屑Expandedvermiculite蛭石ExpandedperliteSandBarite重晶石Sandstone砂巖Basalt玄武巖Magnetite磁鐵礦Hematite赤鐵礦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

堆積密度/松散密度Bulkdensity----isthemassofaggregateperunitbulkvolume.Unit:kg/m3next2.2.8Gradation級配Gradation----referstotheproportions-bymass-ofaggregateparticlesdistributedinspecialparticle-sizeranges.TypesofGradationDense-gradedaggregate----isanaggregatethathasaparticle-sizedistributionthatresultsintheleastvoidsorlowestvoidcontent.Open-gradedaggregate----isanaggregatethathasaparticle-sizedistributionthatresultsinrelativelylargevoidsorvoidcontent.Sieve[siv]篩子SieveAnalysis篩分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分計(jì)篩余(2)Accumulativeremainder累計(jì)篩余(3)Passingpercentage通過百分率(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

細(xì)度模數(shù)FinenessModulus----isafactortoevaluatethedegreeofcoarsenessoftheaggregate.如果有＞4.75mm的，用下公式，否則去掉β1的兩項(xiàng)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

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

單軸抗壓強(qiáng)度Uniaxialcompressionstrength——theultimatestrengthatfailureundertheuniaxialcompressionofthestandardsaturatedaggregate.單軸抗壓強(qiáng)度——石料標(biāo)準(zhǔn)試件吸水飽和后，在單向受壓狀態(tài)下，破壞時(shí)的極限強(qiáng)度。Uniaxialcompressionstrength

單軸抗壓強(qiáng)度JTJ054T0212-94公路工程石料試驗(yàn)規(guī)程50mm×50mm×50mmSaturatedbyabsorptionApplyuniaxialcompressionuntilultimatefailureUniaxialcompressionstrengthWhere,fSC----Uniaxialcompressionstrength;Fmax----loadatultimatefailure;A0----sectionareaofthetestingmaterial.next2.2.12Aggregatecrushingvalue

壓碎值A(chǔ)ggregatecrushingvalue——themeasureofresistingcrushedofaggregateattheincreasingload.壓碎值——用于衡量石料在逐漸增加的荷載下抵抗壓碎的能力。

Aggregatecrushingvalue

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

壓碎值A(chǔ)ggregatecrushingvalueWhere,Cru----Aggregatecrushingvalue(%);m1----Themassofaggregatelessthan3mmaftercrushing;（g）m----Themassofthesample.（g）2.2.13Abrasionvalue

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

洛杉磯磨耗試驗(yàn)粗集料骨架間隙率：4.75mm以上粗集料在搗實(shí)狀態(tài)下顆?？臻g體積的百分含量。用于確定混合料中細(xì)集料和結(jié)合料的數(shù)量，評價(jià)粗集料的骨架結(jié)構(gòu)。細(xì)集料的棱角性：對瀝青混合料抗流動變形能力以及水泥混凝土的和易性十分顯著。間隙率法流動時(shí)間法粗集料的針片狀顆粒含量水泥混凝土-規(guī)準(zhǔn)儀法；瀝青混合料-卡尺法含泥量（細(xì)集料）和泥塊含量（粗集料）其降低水泥水化反應(yīng)速度，削弱集料和瀝青之間的黏結(jié)能力。2.3MixdesignofaggregatesTheoryofgradationMixproportioningdesignmethodofaggregateGradingcurve級配曲線級配理論礦質(zhì)混合料的組成設(shè)計(jì)2.3.1Gradingcurve級配曲線Continuousgradation連續(xù)級配----particle-sizedistributionofanaggregateiscontinuous.Gapgradation間斷級配----oneormoreintermediatesizesofanaggregatearemissing.連續(xù)級配是某一礦質(zhì)混合料在標(biāo)準(zhǔn)篩孔的套篩中篩分時(shí)，所得級配曲線平順圓滑，具有連續(xù)不間斷的性質(zhì)，相鄰粒徑間有一定的比例關(guān)系（按質(zhì)量計(jì)）。Gradingcurve級配曲線Sievesize(mm)ContinuousgradationcurveGapgradationcurvePassingpercentage(%)2.3.2Theoryofgradation級配理論

TheoryofmaximumdensitycurveTheoryofparticleinterference最大密度曲線理論(Fuller)粒子干涉理論(Weymouth)根據(jù)C.A.G魏矛斯（Weymouth）的研究結(jié)果，為達(dá)到最大密度，前一級顆粒之間的空隙，應(yīng)由次一級顆粒所填充；所余空隙又由再次一級小顆粒所填充，但填充空隙的顆粒粒徑不得大于其間隙之距離，否則大小顆粒粒子之間勢必發(fā)生干涉現(xiàn)象，使空隙率增大。

Theoryofmaximumdensitycurve

最大密度曲線理論

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最大密度曲線n冪公式where:p=%finerthanthesieve d=aggregatesizebeingconsidered D=maximumaggregatesizetobeused n=parameterwhichadjustscurveforfinenessorcoarseness(formaximumparticledensityn≈0.5accordingtoFullerandThompson)Particlesizeslgd(mm)Percentpassing(%)npowermaximumdensitycurven冪最大密度曲線OrderNRatioofparticlesizesD/2N-1Particlesizesd(mm)Percentpassing(%)n=0.5n=0.3n=0.7PercentpassingofmaximumdensitycurveandgradationregioncurvePlotofgradationregioncurve

級配范圍曲線的繪制TheoreticalgradationregioncurveSievesizesasabscissa(lgd)Percentpassingasordinate(p)gradationregionn=0.3~0.7Gradationregioncurve

級配范圍曲線GradationregioncurvePassingpercentage(%)Sievesizes(mm)2.3.3Mixdesignofaggregate礦質(zhì)混合料的組成設(shè)計(jì)GraphicalmethodTrialanderrormethod圖解法試算法Graphicalmethod圖解法BalancedareamethodUsealinereplacingthegradationcurve;MaketheareabetweentheleftsideandrightsideequalGraphicalmethod(1)Plotmethodofgradationcurvecoordinates

級配曲線坐標(biāo)圖的繪制方法(2)Methodofdeterminingaggregatesproportion

各種集料用量的確定方法Percentpassing(%)Particlesizes(mm)(1)Plotmethodofgradationcurvecoordinates級配曲線坐標(biāo)圖的繪制方法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

各種集料用量的確定方法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

規(guī)定的級配范圍與中值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繪制級配坐標(biāo)Take10cmasordinate;Take15cmasabscissa;Marktheordinatewithpercentpassing.(2)Determinetheplaceofsievesizeonabscissa

確定各篩孔在橫坐標(biāo)上的位置ConnectdiagonalOO’torepresentgradationmedian;Accordingtotherequiredgradationmedian(percentpassing),findsievesizeonabscissa.(3)Plotgradationcurvesforeachaggregate.

繪制各種集料的級配曲線Percentpassing(%)Sievesize(mm)gradationmedianPlotmethodofgradationcurvecoordinatesPercentpassin