外文翻译-浅谈混凝土的施工过程中温度与裂缝控制

外文翻译一、原文DiscusstheconstructiontemperatureandcrackoftheconcretelightlyThesummary:Inordertopreventtheownersoftheconcreteworkofclaims,wemustdoagoodjobintheconstructionprocessinthetemperatureandcrackcontrol,throughobservationliveformanyyears,throughconsultingthemonographaboutstresswithintheconcrete,explaintoconcretetemperaturereason,on-the-spotconcretecontrolandmeasure,preventionofcrackoftemperaturethatcrackproduce.KeywordConcreteTemperaturestressCrackControl1.Theconcreteoccupiestheimportantpositioninmodernengineeringconstruction.Buttoday,thecrackoftheconcreteiscomparativelygeneral,thecracksarenearlyomnipresentinthescienceofbridgebuilding.Thoughwetakevariouskindsofmeasuresinconstructing,careful,butthecrackstilloccursnowandthen.Tracingittoitscause,itisoneofthemincompletelythatourchangetoconcretetemperaturestresspaysattentionto.Inthelargevolumeconcrete,temperaturestressandtemperaturecontrolaresignificant.Thisismainlybecauseofthereasonoftworespects.Firstofall,concreteoftenappearthetemperaturecrackinnotconstructing,influencetheglobalityanddurabilityofthestructure.Secondly,inthecourseofoperating,thetemperaturechangehasremarkableinfluencethatcan'tbeignoredonthestressstateofthestructure.Wemeettoconstructtemperaturecrackinmainly,soonlytoorigincauseofformationandtreatmentmeasure,concreteofcrackmakeadiscussioninconstructingthistext.ReasonofacrackIthasmanykindsofreasonstoproducethecrackintheconcrete,itismainlythechangesoftemperatureandhumidity,fragilityanddisparityoftheconcrete,andthestructureisunreasonable,therawmaterialsisnotuptostandard(ifthealkaliaggregatereact),thetemplateisoutofshape,thefoundationdoesnotsubsideetc.evenly.Thecementemitsalargeamountofheatofhydrationwhentheconcreteishardened,insidetemperatureisrisingconstantly,causethestressofdrawingonthesurface.Inthecourseofloweringthetemperature,isitcongealfoundationpayrestraintomixalwayslaterstage,willpresentthestressofdrawingwithintheconcrete.Reducingoftemperaturecansurfacecauseheavystressofdrawingveryinconcretetoo.Whenthesedrawthestressandgobeyondresistingtheabilityofsplittingofconcrete,namelywillpresentthecrack.Alotofinsidehumidityofconcretechangeverylightorchangerelativelyslow,surfacehumiditymightchangeheavytheviolentchangetakesplacing.Suchasmaintainingthoroughly,whengettingwetterwhennotdoing,contractsurfacetherearen'tdeformationdoing,oftencausethecracktoo.Theconcreteisakindoffragilitymaterial,tensilestrengthisabout1/10ofthecompressionstrength,isitcarryonone'sshoulderorbacklimitwhendrawoutofshapetohave（0.6～1.0）×104only,isitcarryonone'sshoulderorbacklimitlocationwhenstretchoutofshapetothereis（1.2～2.0）×104toaddforalongtimetoaddashorttime.Becauserawmaterialseven,waterdustthanunstable,transportandbuildphenomenonofemanatingofcourse,itstensilestrengthisnoteveninthesameconcrete,alotofresisttheabilityofdrawingverylow,itisapttopresenttheweakpositionofthecrack.Amongarmoredconcrete,drawstresstoundertakebyreinforcingbarmainly,concretebearstressofkeepingjust.Orreinforcingbarmixifedgepositiongonetocongealpresentsthestressofdrawinginthestructureinplainconcretemustrelyontheconcreteoneselftobear.Requireavoidingthestressofdrawingoronlyverysmallstressofdrawingappearsofthegeneraldesign.Buttheconcreteiscooledfrommaximumtemperaturetothesteadytemperatureofoperatingperiodinconstructing,oftencausesizabletodrawthestresswithintheconcrete.Thetemperaturestresscanexceedotheroutsidesandloadthestressescausedsometimes,knowchangelaw,temperatureofstressforcarryonreasonablestructuraldesignandconstructextremelyimportant.Analysisof2temperaturestressesItcanbedividedintofollowingthreestagesaccordingtotheformingprocessofthetemperaturestress:(1)Itisearly:Itneedsgenerally30dayfrombeginningbuildingconcretetofinishingsendingoutheatbasicallybycement.Therearetwocharacteristicsatthisstage,first,thecementemitsalargeamountofheatofhydration,second,mixandcongealthechangingsharplyofelasticmodelquantity.Becauseofthechangeofelasticmodelquantity,formtheremainingstressintheconcreteinthisperiod.(2)Middleperiod:Uptilltheconcreteiscooleduntilstabilitytemperaturefromcementsendoutheatfunctionbasicallywhenexpiring,inthisperiod,thetemperaturestressismainlybecausethecoolingoftheconcreteandexternaltemperaturechangecause,thesestressesandremnantsstressesthatisformedinearlydaysaresuperposed,mixandcongealtheelasticmouldamountthatgoestoanddoesnotchangemuchduringthisperiod.(3)Laterperiod:Operationperiodafterthecompletecoolingofconcrete.Temperaturestresswhetherexternaltemperaturechangecausesmainly,thesestressesandfirsttwokindsofremnantsstressesarechangedandadded.Itcanbedividedintotwokindsaccordingtothereasonwhythetemperaturestresscauses:(1)Spontaneousstress:Therearenotanyrestraintsortotallystaticstructureattheborder,ifinsidetemperatureisnon-lineardistribution,temperaturestressappearingbecausestructurerestrainsfromeachother.Forexample,thebodyofmoundofthebridge,thephysicaldimensionisrelativelylarge,surfacetemperatureislowwhentheconcreteiscooled,insidetemperatureishigh,presentthestressofdrawingonthesurface,presentthestressofpressinginthemiddle.(2)Restrainthestress:Allofthestructureonesoritrestrainexternalonesomeborder,can'toutofshapeandstressnotcausenotfree.Suchascasebeamroofconcreteandguardrailconcrete.Thesetwokindsoftemperaturestressesdrawbackstressescausedtoactonwiththedoingofconcretetogetherfrequently.Itisamorecomplicatedjobtowanttoanalysethedistribution,sizeofthetemperaturestressaccuratelyaccordingtoknowntemperature.Incaseofgreatmajority,needtorelyonthemodeltestorthenumbervaluetocalculate.Toisitmaketemperaturestresshavesizablelimptocreepconcrete,atthestressaccountingtemperature,mustconsidertheinfluencethatcreep,calculateconcretelythatnolongerstatesthinlyhere.Controlandpreventingthemeasureofthecrackof3temperatureForpreventcrack,lightentemperaturestresscanfromcontroltemperatureandisitisitsetabouttorestraintermsfromtwotoimprove.Themeasureofcontrollingtemperatureisasfollows:(1)Isitimproveaggregategrademix,isitdorigidconcretetospend,mixmixturetoadopt,isitguideangrypharmaceuticalorplastificationpharmaceutical,etc.measureinordertoreducecementconsumptionofconcretetoadd;(2)Addwaterorthewatertocoolthebrokenstoneinordertoreducethetemperatureofbuildingoftheconcretewhilemixingandshuttingtheconcrete;(3)Reducethethicknessofbuildingwhilebuildingtheconcreteonhotday,utilizeandbuildtheaspecttodispeltheheat;(4)Burythewaterpipeundergroundintheconcrete,enterthecoldwatertolowerthetemperatureopenly;(5)Stipulaterationalformremovaltime,thetemperaturekeepswarmthesurfacewhileloweringsuddenly,incasethattherapidtemperaturegradienttakesplaceintheconcretesurface;(6)Theconcretewithmediumandlong-termandexposedconstructionbuildsapieceofsurfaceorthinwallstructure,takethemeasureofkeepingwarmincoldseason;Themeasureofimprovingconditionofrestrainingis:(1)Divideandsewanddivideonerationally;(2)Preventthefoundationfromrisingandfallingtoobig;(3)Rationalarrangementconstructionprocess,preventthetoobigdiscrepancyinelevationandsidefromexposingforalongtime;Inaddition,improvetheperformanceoftheconcreteandimproveandresisttheabilityofsplitting,strengthenmaintenance,preventthesurfacefrombeingdoneandcontracted,especiallyguaranteethequalityoftheconcreteisveryimportanttopreventingthecrack,shouldpayspecialattentiontoavoidingproducingandrunningthroughthecrack,theglobalityresumeditsstructureafterappearingisverydifficult,soshouldrelymainlyonpreventingtheemergenceoftherunningthroughcrackwhileconstructing.Inconstructionofconcrete,forraiseturnoverrateoftemplate,demandconcreteformremovalassoonaspossiblethatbuildnewlyoften.Shouldconsiderformremovaltimeproperlywhenconcretetemperatureishigherthanthetemperature,soasnottocausethesuperficialearlycrackofconcrete.Buildingtheearlyformremovalnewly,causeverylargestressofdrawingonthesurface,thephenomenonthat"temperatureisassaulted"appears.Buildinitialstageinconcrete,becauseheatofhydrationissentout,thesurfacecausessizabletodrawthestress,surfacetemperatureisalsohigherthantemperatureatthismoment,removethetemplateatthismoment,surfacetemperatureisloweredsuddenly,mustcausetemperaturegradient,thusaddanddrawthestressonthesurface,changeandaddwiththeheatofhydrationstress,inaddition,theconcretedriesandcontracts,thesuperficialstressofdrawingreachesverygreatnumbervalue,havedangerofcausingthecrack,butcoveralight-dutyheatinsulatorwithonthesurfaceintimeafterremovingthetemplate,forinstancefoamsponge,etc.,forpreventconcretesurfacefromproducethetoobigstressofdrawing,haveremarkableresults.Addmuscleinfluencetolargevolumetemperaturestressofconcreteverylight,becauselargevolumeconcreteincludemuscletoberateverymuchlow.Justhaveinfluenceonthegeneralarmoredconcrete.Ontermsthattemperatureisnotveryhighandthestressislessthanlimitofsurrendering,everyperformanceofthesteelissteady,andhavenothingtodowithstressstate,timeandtemperature.Linebloatedcoefficientofsteelandconcretelinebloatedcoefficientdifferenceverylight,takeplacelittleinternalstressveryonlybetweenthetwowhilechangingintemperature.Becauseelasticmouldamountofsteelconcreteelasticmould7~15ofquantity,reachasinteriorconcretestresstensilestrengthandwhenfracturing,thestressofthereinforcingbarwillnotexceed10000kg/cm2.Soisitisitpreventtinyappearancedifficultyverymuchofcrackfromtomakeuseofreinforcingbartowantamongconcrete.Butthecrackinthestructuregenerallybecomesnumerous,theintervalislittle,thewidthanddeptharesmallerafteraddingthemuscle.Andifdiameterofreinforcingbardetailedandwhenintervaldense,toimproveconcreteresistresultofpersonwhosplitbetter.Concreteandsurface,armoredconcreteofstructurecantakeplacedetailedandshallowcrackoften,amongthemthegreatmajoritybelongtoanddoanddrawbackthecrack.Thoughthiskindofcrackisgenerallyallrelativelylight,itstillshavecertaininfluenceontheintensityanddurabilityofthestructure.Inordertoguaranteeconcreteprojectquality,preventfracturing,improvethedurabilityoftheconcrete,usetheadmixturetoreduceoneofthemeasuresthatfracturescorrectly.Whetherisitreducewaterisitsplitpharmaceuticaltodefend,Isummarizehismainfunctioninpracticetouse.(1)Thereisalargenumberofcapillaryintheconcrete,producecapillarytensioninthecapillaryafterwaterisevaporated,makeconcreteisitcontractoutofshapetodo.Increasingthethinapertureofhaircanreducethecapillarysurfacetension,butwillmaketheintensityofconcretereduce.Thissurfacetensiontheoryhasalreadybeenconfirmedintheworldasfarbackasthesixties.(2)Waterdustthaninfluenceimportantfactorthatconcreteshrink,isitreducewaterisitsplitpharmaceuticalcanmakeconcretewaterconsumptionreduceby25%todefendtouse.(3)Cementconsumptionimportantfactor,concreteofpersonwhoshrinktoo,isitaddandsubtractwaterisitsplitconcretereducible15%ofthecementconsumptionontermsthatkeeptheintensityofconcreteofpharmaceuticaltodefendtomix,itsvolumeissupplementedbyincreasingaggregateconsumption.(4)Reducewaterisitsplitpharmaceuticalcanimproveconsistencyofgrout,reduceconcretesecreteinktodefend,reduceandsinkanddrawbackdeforming.(5)Improvegluingthestrengthofformingofthegroutandaggregate,theconcreteimprovedresiststheperformanceofsplitting.(6)Concreteisitproducestressofdrawingtorestrainfromwhileshrinking,crackwhendrawingthestressandisgreaterthanconcretetensilestrengthcanproduce.Reducewaterisitsplitpharmaceuticaleffectiveconcretetensilestrengthofimprovementverytodefend,improveresistingtheperformanceofsplittingofconcretebyawidemargin.(7)Itcanmaketheconcretedensitygoodtoaddtheadmixturetomix,canimproveresistingcarbonizationofconcreteeffectively,reducecarbonizationtoshrink.(8)Isitreducewaterisitsplitslowcoagulationtimeproperconcreteunderpharmaceuticaltodefend,onthebasisofpreventingthefastwaterofcementfromsendingoutheateffectivelytomix,preventtheplasticityshrinkthatbringsbecausethecementisnotcongealedforalongtimefromincreasing.(9)Mixadmixtureconcreteandgettingeasyandkind,surfaceeasytofeelflat,formlittlemembrane,reducethemoisturetoevaporate,reducedrilyandshrink.Alotofadmixturesallhavethefunctionsofslowcoagulation,increasingandapt,improvementplasticity,theexperimentthatweshouldcarryoninthisrespectmoreintheprojectpracticeiscomparedwithandstudied,thanleanagainstnotimprovingtermsmoresimple,maygettingsimpleandmoredirect,economy.Earlymaintenanceof4concretePracticehasproved,thecommoncrackofconcrete,mostisthesurfacecrackofdifferentdepth,mainreasonitswhethertemperaturegradientcausecoldtemperatureofarealowertooeasytoformcracksuddenly.Sosaythewarm-keepingoftheconcreteisespeciallyimportanttopreventingtheearlycrackofsurface.Fromtheviewpointoftemperaturestress,shouldreachandrequirekeepingwarmfollowing:1)Preventconcreteinternalandexternaltemperaturepoorandconcretesurfacegradientfrom,preventthesurfacecrack.2)Preventconcretefromtobeultraandcold,shouldisitisitmaketheminimumtemperatureisnotlowerthanthesteadytemperatureofconcreteservicetimeconstructiontimeinconcretetotrytotryone'sbest.3)Preventtheoldconcretesubcooling,inordertoreducetherestraintamongtheoldandnewconcrete.Theearlymaintenanceoftheconcrete,themainpurposeliesinkeepingthesuitablewarmandhumidcondition,inordertogettheresultoftworespects,ontheotherhandmaketheconcreteavoidtheinvasionandattackoftheunfavorableandwarm,humidityoutofshape,theonesthatpreventfromharmfullyarecoldtocontractanddotocontract.Ononehandmakecementwaterfunctiongoonsmoothly,isinthehopeofreachingtheintensitydesignedandresistingtheabilityofsplitting.Thesuitablewarmdampconditionisinterrelated.Mixwarm-keepingmeasurepaidtocongealoftenprotectswetresultstoo.Analyse,waterconcreteincludemoisturecanmeetdemand,cementofwaterhaveenoughandtosparenewlytheoretically.Butbecausethereasonofevaporatingetc.oftencauseslossesofthemoisture,thuspostponeorhinderwaterofthecementfrom,thesurfaceconcretereceivesthiskindofadverseeffecteasiestlyanddirectly.Keyperiodwhenmaintainedininitialafewdaysaftersotheconcreteisbuiltshouldpayattentiontoconscientiouslyinconstructing.2.QualitycontrolofwaterproofconcreteconstructionCombinedwithexperience,fromformworkdesign,fabricationandinstallation,assemblingreinforcement,pouringandcuringofconcreteandotheraspectsconstructiontechnologyoffair-facedconcreteisintroducedaswellasqualitycontrolmeasuresandstandardsinordertoreduceengineeringcosttoacquiresatisfiedeconomicandsocialbenefits.Thefactorsofinfluencingwaterproof-concretequalityareverymany.Anylinksdoesnotpayattentiontothewater-proofconcreteoffieldlosshindersthewaterfunctionwithoutexceptionjointlywithdegree.Engineeringconstructioninthebasementadoptssecondaryformboardfabricationandinstallation,reinforcedbarfabricationandbind,concretestirringandmixingsystemandtransport,concretecovibrationbeatwithastick,constructionjointpractice,concretecuringanddismantlemodelandbeingreadyforbackfillandsoonaspects.Theseareverycriticaltoqualitymethodtoensurethatwater-proofconcreteselfwater-proof,andthewayofpracticehaswanout.Methodbeingunderconstruction2.1FabricationandInstallationAccordingtotheconcertofcloselyknit,demandofreasonwhytoformboardsincethewater-proofalsoconcretehavemadeandhaveassembledcorrespondingriseisspecial,betorequirethatnotleavingoutthickfluid,firmcloselyknitblockofwooddeformation,waterabsorptionCharactershouldbesmallandoughttogiveprioritytoselectandusingbambooslabrubberformboardorthesteelform..Strictcontrolformboardroomgapsize,necessaryexceeding2mmsusesfoamrubberorplastictosqueezeacrackin,porousformboardnonutilitywithoutexceptiontoboardfaceBereadyforwallpostatthesametimerottingthepreventionandcurejobadoptthecementmortarpouringsame,indiciainbeforetherootsegmentstickingthefoamrubberorplasticstrip,thebottomputsonacementmortar,concreteaconcrete,first5cm~10cm.Sincewater-proof,concretestructurewallthicknessismostlymoreinfertile.Betoensurethatcomponentgeometrydimension,Changadopttheinsideandoutsidebolttopullthemeasuremeetingattentionto,respondstoonplayreceiveboltcentreinterposestopwaterironplate,topreventwaterfromformingpilotagepassagealongboltleakage.2.2AssemblingreinforcementWater-proofconcretestructurehasdemandingasfollowstothereinforcedbar:1)Reinforcedbarshouldadopttwistedsteelasfaraspossible,increasesbyholdwrapaforcecomposinginreplyawaterability2)Reinforcedbarsconnectshouldtryone'sbesttoadopttosolderconnection,stopusingandbeingneedlesstobindconnectiontothefull3)Whenbindingareinforcedbar,theironwireheadrespondstoinnerbending.4)Strictcontrolreinforcedbarsprotectivelayerthickness.Minimalthicknessofwater-proofconcretereinforcedbarprotectivelayerisnotsmallerthan25mms,theprotectivelayerwelcomingwatersurfaceespeciallyinadmissibilitytodisappointerror.Theironwireandreinforcedbarthatapplicationburiesinadvancewithinmortarpiecewhileusingmortarheelblockasprotectivelayer,areboundsolid.Whenthecavalryputsupthefixedreinforcedbarifadoptareinforcedbar,alsoneedtoincreasesolderswaterironplateorfixationjustgoesahead,tostrengthenwater-proofeffectintheheelblock.Thisprojectusesnewmaterialsnylontohavefixedthereisaneffect'shadguardedagainstreinforcedbarprotectivelayerdeviationpiecebigmasscommonfailings.2.3TheconcretestirringandmixingmakesandtransportsSincethewater-proofconcreterequiresthathighercloselyknit,reasonwhystirandmixsystemalsoneedtohavethefairlygoodhomogeneity,shouldbereadyforburningasfollowsalmostforthispurpose:1)Ensuresthatmixingtime,mixingateverytimearesecondaryjumpintoaexpectthegeneralejectionofcompactblockofwoodlessthan2mins.2)Shouldusetheappositionagent,thesolutionqueenwhoshouldmanufacturecertainthicknessfromappositionagentaddsthemixerinner,thedriedpowderorhighconcentrationsolutionwilladdanagentextranottoaddsthemixerinnerdirectly,preventfrommixingisunevenbutpartconcentrates,bothlosetheappositionagenteffect,andaffectconcretemass.3)Respondstotheassuredsourceoflifedegreehavingaspottestontheadmeasurementconcreteattheregularintervalscollapsingintheprocessbeingunderconstruction,constructionismiddleifYurainsorothercause,respondtotheratiodeterminingwhosewaterratio,andadjustingthecompositionbeingunderconstructionintimewhenchangehappenedinsandstonemoisturecontent.4)Projectusesthecommodityconcrete,hasboundaryhaveraisedaconcretestirringmassandofallkindseffectappositionagentadulteratingfallswhenamounts,thewaterashhavingcontrolledaconcretestrictlycollapsing.5)Concretesadoptapumptohavegivenhandicraft,effectiveavoidingaconcreteproducingthephenomenonisolatingbleedingandleavingoutthickfluidintheprocessoftransportation.2.4Mattersneedingattentioninbeingunderconstruction1)Constructionschoolassignmentsoftandflouryisdivided.Water-proofconcretingshouldstratifystrictlybeinginprogress,andacontinuousconstructioniscompletedThefrontandbackandhighandlowconnectbetweenthetiershouldsubjugatewithinthecementinitialsettingtime,Forthispurpose,withhandlingaworkerdividingintoseveral,atthesametimeeachother,schoolassignmentgroupfacesoritisallrightforeachother,carryontheback.2)AchievestrictlyfixedpointdeterminestheamountsofthecomponentsofasubstancematerialdownAccordingtothevehiclecapacitiesstratifyingconcretealtitudeandthemeansoftransport,thequantifycarryingoutfixedpointstrictlyisabletogodownoneimportantringexpectingthatthisistoimprovewater-proofconcretingmass.3)Concretesvibratingbeatoneimportantringbeingtoensurethattheconcreteiscloselyknit,defendagainsttoseepwithastick.Also,shouldadoptfixedpointvibrating,handlemeticulouslyonbasisexpectingthatunderdeterminingtheamountsofthecomponentsofasubstancehomogeneouslyinfixedpoint.Payattentiontohighandlowtieroflinkingup.Nowthatneedingtopreventfrommissandvibrating,notvibratingenough,beinggoingtopreventafaultfromvibratingagain,Needtoforbidusingpryingthemethodcomingtoaidtovibratemovingareinforcedbarorshakingareinforcedbarespecially,suchseparatestomakingthefrontalreadyconcretethereinforcedbarandconcreteshakingtherealitypart,causesseriousconsequences.4)Beingreadyfortheassuredsourceoflifedegreetakingoverthickfluidmeasure,andadjustingintimetocollapseseriously.Averagewater-proofconcretestructureconstruction,theconstructionjointbeingunderconstructionrespectively,composingnamelyonerectingwallsellsbebottomboardandverticalwallatreducedprices.Shouldirrigatethickalayerof5cm~10cmssurnameindiciacementmortarsinseamplacefirstlinkingupcloselyknittingtier,inordertoensuringthattheseamplacevibrateswhenconcreteverticalwall.Simultaneous,improvestepbystepwithconcreteanaltitude,shouldfalloffstepbystepwiththewateryield,diminishcollapsingtofalldegreepreventfromconcreteinsisttobeshortbutthecementpasteispartialtomuchphenomenontoaggregateappearingonupperpart.2.5DismantlingmodelandcuringofconcreteThewater-proofconcretingqueenmaintainsgoodnessandbadnessworking,notonlyaffectingtheintensityarrivingataconcrete,moreovertheimperviousfunctionaffectingtotheconcrete.Evidence,water-proofconcreteearlyphasedehydrationorcuringprocesslackforwater,willreducewhoseimperviousfunctionbyawidemargin.Water-proofconcretecuringrespondstotheblockofwoodlessthan14ds.Thewater-proofconcretedismantlesamodeldemandingtobeunabletocomparehigh,dismantlemodeltimeunsuitableuntimely,respondtowhendismantlingamodelhandlemeticulously,preventanironrodfromusingtoprystiffly,thatthesledgehammerisknockedsuddenlyandforciblypries,usesaconcretemeetwithdestroy.2.6DogoodwellatbackfillWater-proofarchitecturalbackfillisafinalworkingprocedure,itbesometimesignored,thisisaverybigfaultsinfactundertheground.Whenthewater-proofstructurejobisoverqueenrespondstotheconstructioncarryingoutbackfillimmediately.Mostimportant,weshouldtakebackfillseriouslyselfmass;Secondly,backfillvariaandpondingshouldclearupthepitbottominthefront,respondtodensificationwithlayerswhenbackfill.Water-proofstructurevicinitylayerpoundstruebackfill,selfisareliableandeconomicalaswellwaterproofingdraperyundertheground.InprojectbasementengineeringconstructionShanghai,sinceorganizingwaterproofingdowntoearthstrictlywithallabovesevenpasses,theconcreteisunderconstruction,effectiscomparativelyideal.Thepercolatingwaterphenomenondoesnotappear.ConclusionsConstructiontemperatureandrelationofcrackinconcretetheabovecarryonpreliminarydiscussionoftheoryandpractice,thoughtheacademiahasdifferenttheoriestoorigincauseofformationandcomputingtechnologyoftheconcretecrack,buttoconcretepreventionandimprovingthemeasuresuggestiontorelativelyunify,applicationinpracticeresultfinetooatthesametime,concretetoisitobserve,comparemorebyustowantinconstructing,analysemore,summarizemoreaftergoingwrong,combinemanykindsofpreventionanddealwiththemeasure,thecrackoftheconcretecanbeavoided.翻译浅谈混凝土的施工过程中温度与裂缝控制摘要为了防止业主对混凝土工程的索要赔偿,我们就必须做好过程中的温度与裂缝控制。本文通过多年的现场观察，通过查阅有关混凝土内部应力方面的专著，对混凝土温度裂缝产生的原因、现场混凝土温度的控制和预防裂缝的措施进行等进行阐述。关键词：混凝土温度应力裂缝控制1.混凝土在现代工程建设中占有重要地位。而在今天，混凝土的裂缝较为常见，在桥梁工程中裂缝更多。尽管我们在施工中采取各种措施，但裂缝仍然时有出现。究其原因，我们对混凝土温度应力的变化注意不够是其中之一。在大体积混凝土中，温度应力及温度控制具有重要意义。这主要是由于两方面的原因。首先，在施工中混凝土常常出现温度裂缝，影响到结构的整体性和耐久性。另外，在运转过程中，温度变化对结构的应力状态具有显著的不容忽视的影响。我们遇到的主要是施工中的温度裂缝，因此本文仅对施工中裂缝的成因和处理措施做一探讨。1）裂缝的原因混凝土中产生裂缝有多种原因，主要是温度和湿度的变化，混凝土的脆性和不均匀性，以及结构不合理，原材料不合格（如碱骨料反应），模板变形，基础不均匀沉降等。混凝土硬化期间水泥放出大量水化热，内部温度不断上升，在表面引起拉应力。后期在降温过程中，由于受到基础或老混凝上的约束，又会在混凝土内部出现拉应力。气温的降低也会在混凝土表面引起很大的拉应力。当这些拉应力超出混凝土的抗裂能力时，即会出现裂缝。许多混凝土的内部湿度变化很小或变化较慢，但表面湿度可能变化较大或发生剧烈变化。如养护不周、时干时湿，表面干缩形变受到内部混凝土的约束，也往往导致裂缝。混凝土是一种脆性材料，抗拉强度是抗压强度的1/10左右，短期加荷时的极限拉伸变形只有（0.6～1.0）×104，长期加荷时的极限位伸变形也只有（1.2～2.0）×104。由于原材料不均匀，水灰比不稳定，及运输和浇筑过程中的离析现象，在同一块混凝土中其抗拉强度又是不均匀的，存在着许多抗拉能力很低，易于出现裂缝的薄弱部位。在素混凝土内或钢筋混凝上的边缘部位如果结构内出现了拉应力，则须依靠混凝土自身承担。一般设计中均要求