外文翻译(中英文)低成本防水材料的制备Word文件下载.doc
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arbin150001,China,E-mail;
abd—et76@yahoo.con)
Abstract:
Toaddresstheneedforproducingacheap,single—component,hot-appliedcompoundjointsealantwithhighqualityforsealingjointsandcracksinconcreteandflexiblepavementswithoutusingprimerforinstallation,ahot-appliedmodifledasphaltsealantwasproducedbyblendingupabout30%starchinto20%citricacid.
Thestarchandtheasphaltcementweremixedatatemperatureofabove160℃.Thusthewaterproofingasphaltwasmanufacturedtoprotectthesurfaceofvariousshapesandtypesfromwaterleakageusingthecitricacid.ResultsindicatethatthissealantcomplieswiththerequirementsofASTMD-1191,D-6690-06aandD-7116-05.Thecitricacidisakindofreliablematerialsforasphaltcement,whichcanbewidelyusedinpavingandwaterproofingconstructionmaterials,andthisoffersprofoundengineeringandeconomicadvantages/
Keywords:
jointsealant;
starch;
citricacid;
waterproofingmaterial;
pavingasphalt
CLCnumber:
U214Documentcode:
AArticleID:
1005-9l13(2008)04-0547-06
1BackgroundoftheStudy
Thepresentstudyrelatestowaterproofingmaterials,andinparticulartowater-
proofingasphaltcementandjointsealant.
Jointsealantandwaterproofingasphaltisregardedasoneoftheimportantprimarymaterialsusedinthefieldofcivilengineeringwork.Theirselectionmustalwaysbeamatterofcompromisebetweenpriceandperformance.Forexample,Cracktreatment,includingcracksealing,crackfilling,andcrackrepair,isoneofthemostcommonmaintenanceactivitiesperformedonbituminouspavementsbylocalgovernmentalagencies.Cracksealingisthemethodofplacingmaterialinacracktocreateawatertightbarrier.Transverseandlongitudinalcracksealingisperformedfrequentlyinordertoextendpavementlifebypreventingorsubstantiallyreducingtheinfiltrationofwaterintothepavementstructure.
Sealingcracksinasphaltpavementshaslongbeenregardedasanannualpreventivemaintenanceprocedureandisexpectedtohaveagrowthrateof3%-4%peryear.Withlimitedmaintenancebudgetsandincreasinglaborandmaterialcosts,so-
memeansofreducingthelife,cyclecostofcracksealsisrequired.Polymermodifiedasphaltcracksealermaterials,asdefinedbyAmericanSocietyforTestingandMaterials[1,2],havedemonstratedthepotentialtodeliver5ormoreyearsofservicelife.Becausethepolymermodifiersthathavebeenemployedbeneficiallyasasphaltmodifiersareratherexpensive,aneedexistsforalternative,lower-costmodifiersthatnonethelessimpartimprovedpropertiescomparabletothoseachivedbyusingthemoreexpensivepolymers.
Highwayagenciesusedifferentmaterialsandmethodstotreatcracksinasphahconcretepavements.Someofthesetreatmentsareinherentlybetterthanothers;
howe-
ver,theuseofstarchasamodifierhasnotbeeninvestigatedbyotherresearchersintheworld.
Substantialquantitiesofstarcharepotentiallyavailablewidelyintheworld.
Starchisafinewhitepowdermainlycomposedoftwocarbohydratepolymers,amy-
loseandamylopection.Itcharacterizedwithlowweightisgenerallymuchcheaper(0.8$/kg)thanotherconventionalpolymerssuchas,styrene-butadiene-styrene,polyethy-
lene,andpolypropylene.Starchgranulesizevariesfrom(1-100)micronsindimeterandshape.Ontheotherhand,beta-hydroxytrisarboxy1ic(citric)acidisafinewhitepowderwithanaverageparticalsizeof100mesh.Citricacidisaveryusefulandeffectivepreservative,obtainedfromnaturallyoecurringorganicacids.Itconsistsof10ppmheavymeatal,150ppmsulphate,notmorethan0.1percentsulphateash,0.2ppmaluminum,lessthan3ppmash,and350ppmoxalate.Thesecharacteristicsmakescitricacidandstarchespeciallydesirabletodeveloplowcost-effectivewaterproofingmaterials.
Thecausesofsealantfailuredependonthetypesofsealantused,installationandserviceconditions.Sealantasamaterialcanfailduetoageandweatherexposure.Thistypeoffailureisoftencharacterisedbydiscolouration,crazingandstiffeningofthesealantsurfaces,andistheresultoftheindividualorcombinedeffectsofsolventevaporation,ozoneattack,migrationofplasticisers,ultravioletradiation,etc.Failurecanalsooccurifthereisalargeointmovementbeforethesealisfullycured.Inothercases,sealantfailuresoccurbecausethesealantsarerequiredtotakecyclicmovementsbeyondtheirlimits.
ThevariousmodesoffailureexperiencedwithsealantsinserviceareillustratedinFig.1[3,4].
①AdhesionFailure
Thisisthemostcommontypeoffailureduetothelossofbondbetweenthesealantandthesubstrate(Fig.2)[3,4].
②Cohesionfailure
Thisis