外文文献及译文玻璃纤维对于沥青稳固性影响的研究.docx

外文文献及译文玻璃纤维对于沥青稳固性影响的研究.docx

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外文文献及译文玻璃纤维对于沥青稳固性影响的研究

唐山学院

毕业设计

外文资料翻译

系别：

土木工程系

班级：

07级土木工程

（2）班

姓　　名：

赵菲

指导教师：

贾开武

2006年6月13日

一.英文原文

ASTUDYONTHEEFFECTOFGLASSFIBREONTHESTABILITYOFBITUMINOUSMIXES

S.JAYALEKSHMI1andN.ANJANEYULU²

ABSTRACT:

Surfacecrackingofpavementsdecreasesitsfatigueresponse.Theinclusionofglassfibreinbituminousmixesincreasesthefatiguelifeofpavements.InthecurrentinvestigationE–glassfibreismixedwiththebituminousmixesandMarshallStabilitytestwasconducted.Theoptimumbitumencontentandflowvaluewereevaluated.Theinfluenceofthisglassfibreondurabilityandtheengineeringpropertiesofsemidensebituminousconcretesuchasstability,flow,airvoidsinthemix,voidsinmineralaggregatesandvoidsfilledwithbitumenarepresentedinthispaper.Thestabilityvaluesincreasedbyasmuchas32%.

KEYWORDS:

FibreGlass,BituminousMixes,MarshallStabilityTest,Stability,FlowValue

1.INTRODUCTION

Thelowtensilestrengthofbituminousmixescausesthepavementsubjectedtorepeatedloadingtocrack.Thepropagatedcracksdevelopdistresssymptomslikeraveling,undulations,rutting,cracking,bleeding,shovingandpotholingofbituminoussurfacing.Thehightrafficintensityofcommercialvehiclesalsocompoundsthisproblem.Hence,toimprovetheperformanceofthepavements,reinforcementsandadditivesareaddedtothebituminousmixes.Therefore,therearisesanecessitytoevaluatetheoptimumfibrecontentandthetypeoffibre.Thefibresplacedinthebituminousmixarehomogeneouslydispersedandactasstressabsorbinglayers.Intherecentpast,cotton,metalwireandasbestoswereused.Cottonisdegradableandcannotbeusedaslongtermreinforcement;metalwirerustswhenwaterpenetrates.Asbestosposeshealthhazard.Thisautomaticallyleadstothechoiceofglassfibre.Transportationisthelifelineofanynation'seconomyandhenceimprovingtheperformanceofthepavementsindirectlybooststheeconomy.

2.REVIEWOFLITERATURE

Freeman（1978）foundthattheincorporationofpolyesterfibreasareinforcementinthesurfacecourse,reducesreflectivecracking.Theeffectwasstudiedbyvaryingthediameter,lengthandpercentageofthepolyesterfibre.Gokhale（1987）carriedoutstudiesonreinforcedbituminoussurfaceswithfibreglasssheetandTeflonsheetsandwithfivetypesofgradationsofmineralaggregates.Kim（1999）evaluatedtheperformanceofpolymer-modified（polypropylenefilmandagrid）bituminousmixturesandspeciallydesignedreinforcingtechniqueagainstreflectivecrackingfortypicalbituminouspavementoverlayers.ThewheeltrackingtestwasusedtoinvestigatedurabilityaspectssuchastheplasticflowresistanceandcrackresistanceofthegeogridreinforcedbituminousmixturesbyKomatsu（1998）.Thematerialusedwasahighstrength,highmoduluspolyoxymethylenefibre.AsperLytton（1989）,theuseofgeotextilesinbituminousoverlaysenhancesreinforcing,strainreliefandundersealing.Thereflectioncrackingcausedbytheloadsandthermalcontractionwasarrestedbytheuseofgeotextilereinforcement.Maurer（1989）determinedtheeffectivenessofvariousgeotextilesandfibresinretardingthereflectivecrackformationinbituminousoverlay.Thefatiguelifeandtherutresistancealsoimproved.ThecheapesttypeofglassfibreavailablecommerciallyistheE-GlassFibreandthismaterialisusedinthepresentstudyasreinforcementwithinthebituminousmix.

3.LABORATORYSTUDY

MATERIALPROPERTIES

3.1.1GlassFibre

ThepropertiesoftheE-GlassFibreusedareaslistedinTable1.

3.1.2Aggregate

TheaggregateusedinthestudyisofthegradationspecifiedbytheMORT&H（SpecificationsforRoadandBridgeWorks（2001））for25-30mmthickSemi-DenseBituminousConcrete（GradeII）.ThisisthemostwidelyusedsurfacecourseforhighwaysinIndia.TestsconductedontheaggregateshowedthematerialpropertiesindicatedinTable2.

Correctsampling（Representativesample）wasensuredascorrectnessoftheMarshallStabilityTestlargelydependsonpropersampling.Therequiredgradationwasarrivedatbybatchmixingbycarefullyproportioningtwoorthreesizesofaggregatemixtures.Thenominalsizeoftheaggregateis10mm.Thelayerthicknessis25mm-30mm.ThegradationisasshowninTable3.TheSemiDenseBituminousPavementLayershaveaminimumstabilityofkNat60℃.Theflowis2mmto4mm.Compactionisachievedbygiving75blowsoneachofthetwofacesofthespecimen.Thepercentageofairvoidsis3-5.Thepercentageofvoidsfilledwithbitumenis65-78.

3.1.3Bitumen

TheengineeringpropertiesofBitumenusedinthestudyarelistedinTable4.Both60/70gradebitumenand80/100bitumenwereusedinthestudy.

4.METHODOLOGY

Bitumenandaggregateformthemajorconstituentsofthesurfacelayerofaflexiblepavement.Thefollowingpropertieswereevaluated.

Bitumen:

Penetration,softeningpoint,ductility,specificgravity.

Aggregate:

Crushingvalue,impactvalue,abrasionvalue,flakinessindex,elongationindex,waterabsorption,specificgravity.

GradationofSemiDenseBituminousConcreteusuallyusedforsurfacelayersoftheflexiblepavementsinIndiahasbeenselectedforthepresentstudy.

Allthetestswereperformedaccordingtothestandards.MarshallMethodofmixdesignwascarriedoutonglassfiberreinforcedandunreinforcedbituminousmixestoarriveatoptimumfibercontentandoptimumbindercontent.

Followingarethevariablessetforthepresentstudy:

􀂃Fiberpercentagesof0,,,,,

􀂃Gradeofbitumen:

60/70and80/100

Thedimensionsoftheglassfiberusedareasfollows;

􀂃Glassfiberlength:

12.5mm

􀂃Diameterofglassfiber:

5-10μm

Itisimportanttocharacterizethevariouspavementmaterialsandfindtheoptimumconditionsfortesting.Glassfiberavailableinthelocalmarketisusedasreinforcementfortheexperimentalinvestigation.Toeliminateanypossibilityoferrorsinsamplingforpreparingbatchmixes,amixhasbeenpreparedthathasthegradationaroundthemid-valueofthegradationlimitsgiveninTable.Thus,oneparameterofgradationofaggregatehasbeenfixed.MarshallStabilityandflowvalueshavebeenusedasparametersfortheassessmentofthestrengthofthepavement.TheMarshallStabilitytesthasbeencarriedoutatvariouspercentagesofthefibre,toarriveattheoptimumpercentageoftheglassfiberthatgivesmaximumstabilityandaflowwithinspecificationlimits.

5.RESULTSANDDISCUSSION

Forvariousbindercontents,thevaluesofstability,flow,unitweight,percentagevoidsandpercentageaggregatevoidswereexaminedforthereinforcedandun-reinforcedbitumen.Fortheunreinforcedcase,theMarshallStabilityvaluesfordifferentbitumencontentsisasshowninFigure1TheMarshallstabilityvalueincreaseswiththebitumencontentuntilitreachesapeakvaluecorrespondingto%for60/70gradebitumenand%for80/100gradebitumen.Thevariationofbulkdensityandpercentageairvoidswiththebitumencontentwasalsoexamined.Thebulkdensityvs.bitumencontentvariationisplottedinFigure2.

Thepercentageairvoidsvs.bitumencontentvariationisasshowninFigure3.

FromFigure1,Figure2andFigure3,theoptimumbitumencontentfor60/70gradebitumenisfoundtobe%andthatfor80/100bitumenisfoundtobe%.

Figure4andFigure5showthevariationofbulkdensitywithfibrecontentfor60/70and80/100gradebitumenrespectively.

Atafibrecontentof%,theoptimumbitumencontentforreinforcedmixis%.Forhighergradesofbitumen,thestabilitydecreasesbecauseofinsufficientbondagebetweenaggregates,fibreandbitumen.Theflowwasfoundtobewithinthelimitsof2-4mmasspecifiedbyMORT&H2001（SpecificationsforRoadandBridgeWorks）Thereisanegligblechangeinunitweight.

6.CONCLUSIONS

Basedontheexperimentalinvestigationonglassfiberreinforcedbituminousmix,thefollowingconclusionsweredrawn:

About20to32percentincreaseinstabilityvaluescanbeachievedbyreinforcingthebituminousmixwithglassfiber.HigherstabilityvaluesindicatethatthereinforcedmixeswouldbelesssusceptibletocrackingofFlexiblepavements.

FromtheMarshallStabilitytestsconducted,anoptimumfibercontentof%bytheweightoftotalmixwasfoundforabitumencontentof%.

Fortheoptimumfibercontent,themaximumstabilityvaluewasfoundtobekNforabitumencontentof%.

Theservicelifeofthepavementisexpectedtoincreaseafterreinforcingthebituminousmixwithglassfiber.

Fromtheobservedimprovementsinstabilityandengineeringproperties,itcanbeconcludedthatthereinforcedbituminousmixesaresuitableinheavytrafficconditionsalso.

7.REFERENCES

1.Freeman,.,BuratiJr.,.,Amirkhanian,.,andBridgesJr.,.（1989）.“Polyesterfibreinasphaltpavingmixtures,”Proceedings,AssociationofAsphaltPavingTechnologists,Vol.58pp387-409.

2..andSingh.,（1987）.“Laboratorystudyonflexuralfatigue

characteristicsofreinforcedbituminoussurfacings,”HighwayResearchBulletin,No.32,pp45-56.

3.Khanna,.,andJusto,（1992）.“HighwayMaterialTesting,”NemChand&Bros.Roorkee,India.

4.Khanna,.,andJusto,（1992）.“HighwayEngineering,”NemChand&Bros.,Roorkee,India.

5.Kim,.,Doh,.,andLim,S.（1999）.“ModeIreflectioncrackingresistanceofstrengthenedasphaltconcretes,”ConstructionandBuildingMaterials,Vol.13,pp.243-251.

6.Komatsu,T.,Kikuta,H.,Tuji,Y.,andMuramatsu,E.（1998）.“Durabilityassessmentofgeogridreinforcedasphaltconcrete,”Geo-textilesandGeo-membranes,Vol.16,pp257-271.

7.Lytton,.（1989）.“Useofgeo-textilesforreinfo