合肥學院畢業設計外文翻譯課題名稱中興?文華園7#樓施工組織設計姓名學號院、系、部建筑工程系專業班級工程管理專業指導教師2013BuildingconstructionconcretecrackofpreventionandprocessingDimosiM《CANADIANJOURNALOFCIVILENGINEERING》Abstract：Thecrackproblemofconcreteisawidespreadexistencebutagaindifficultinsolveofengineeringactualproblem,thistextcarriedonastudyanalysistoalittlebitfamiliarcrackproblemintheconcreteengineering,andaimatconcretethecircumstanceputforwardsomeprevention,processingmeasure.Keyword:ConcretecrackpreventionprocessingForewordConcrete'sising1kindisanticipatebythefreestonebone,cement,waterandothermixturebutformationoftheinadditionmaterialofqualitybrittlenessnotandallmaterial.Becausetheconcreteconstructiontransformwithoneself,controletc.aseriesproblem,hardenmodelofintheconcreteexistencenumeroustinyhole,spiritcaveandtinycrack,isexactlybecausethesebeginningstartblemishofexistencejustmaketheconcretepresentonesomenotandallthecharacteristicofquality.Thetinycrackisakindofharmlesscrackandacceptconcreteheavy,defendpermeationandalittlebitotherusefunctionnotacreationtoendanger.Butaftertheconcretebesubjectedtolotuscarry,differenceintemperatureetc.function,tinycrackwouldcontinuouslyofexpandwithconnect,endformationwecanseewithouttheaidofinstrumentsofmacroviewthecrackbealsothecrackthattheconcreteoftensayintheengineering.ConcretebuildingandGoupieceusuallyalltakesewertomakeof,becauseofcrackofexistenceanddevelopmentusuallymakeinnerpartofreinforcingbaretc.materialcreationdecay,lowerreinforcedconcretematerialofloadingability,durableandanti-permeationability,influencebuildingofexternalappearance,servicelife,severitywillthreatarrivepeople'slifeandpropertysafety.Alotofallofcrashofengineeringisbecauseoftheunsteadydevelopmentofthecrackwiththeresultthat.Modernagescienceresearchwithagreatdealoftheconcreteengineeringpracticecertificate,intheconcreteengineeringcrackproblemisineluctable,alsoacceptableincertainlyofthescopejustneedtoadoptvalidofmeasurewillitendangerdegreecontrolatcertainofscopeinside.Thereinforcedconcretenormisalsoexplicitprovision:Somestructureatplaceofdissimilarityundertheconditionallowexistencecertainthecrackofwidth.Butatunderconstructionshouldasfaraspossibleadoptavalidmeasurecontrolcrackcreation,makethestructuredon'tappearcrackpossiblyorasfaraspossibledecreasecrackofamountandwidth,particularlywanttoasfaraspossibleavoidharmfulcrackofemergence,insureengineeringqualitythus.Concretecrackcreationofthereasonbealotofandhavealreadytransformedtocauseofcrack:Suchastemperaturevariety,constringency,inflation,theasymmetrysinktosinketc.reasoncauseofcrack;Haveoutsidecarrythecrackthatthefunctioncause;Protectedenvironmentnotappropriatethecracketc.causedwithchemicaleffect.Wantdifferentiationtotreatintheactualengineering,workoutaproblemaccordingtotheactualcircumstance.Intheconcreteengineeringthefamiliarcrackandtheprevention1.DesiccationfissureandpreventionDesiccationfissurecrackmuchappearaftertheconcreteprotectbeoverofaperiodoftimeorconcretesprinkletobuildtocompletebehindofaroundaweek.Inthecementsyruphumidityofevaporatewouldcreationdesiccation,andthiskindofconstringencyiscan'tnegative.Desiccationfissurecrackofthecreationbemainisbecauseofconcreteinsideoutsidehumidityevaporatedegreedissimilaritybutcausetotransformdissimilarityofresult:Theconcreteissubjectedtoexteriorconditionofinfluence,surfacehumiditylossleadquick,transformbigger,innerpartdegreeofhumidityvarietysmallertransformsmaller,biggersurfacestemtheshrinktransformtobesubjectedtoconcreteinnerpartcontrol,creationmorebigpullshoulddintbutcreationcrack.Therelativehumidityismorelow,cementsyrupbodystemshrinkmorebig,stemtheshrinkcrackbemoreeasycreation.Desiccationfissure-0.2mm,theflatsurfacepartmuchseeinthebigphysicalvolumeconcreteandfollowitmoreinthinnerbeamplankshorttodistribute.Desiccationfissurusuallytheanti-extendofinfluenceconcrete,causethedurableoftherusteclipseinfluenceconcreteofreinforcingbar,underthefunctionofthewaterpressuredintwouldcreationthewaterpowersplitcrackinfluenceconcreteofloadingdintetc.Concretestemtheshrinkbemainwithwaterashoftheconcreteratio,thedosageofthecomposition,cementofcement,gathertoanticipateofthedosageofthepropertyanddosage,inadditionetc.relevant.Mainpreventionmeasure:Whilebeingtochoosetousetheconstringencyquantitysmallercement,generallowhotwatermireandpowderashfromstovecementintheadoption,lowerthedosageofcement.Twoisaconcreteofstemtheshrinkbesubjectedtowaterashratioofinfluencemorebig,waterashratiomorebig,stemshrinkmorebig,sointheconcretematchtheratiothedesignshouldasfaraspossiblecontrolgoodwaterashratioofchoosetouse,theChanaddinthemeantimeaccommodationofreducewater.Threeisstrictcontrolconcretemixblendwithunderconstructionofmatchratio,useofconcretewaterquantityabsolutecan'tbiginmatchratiodesigngivesettleofusewaterquantity.Fouristheearlierperiodwhichstrengthenconcretetoprotect,andappropriateextensionprotectofconcretetime.Winterconstructionwanttobeappropriateextensionconcreteheatpreservationtooverlaytime,andtoprotect.Fiveisaconstitutiontheaccommodationisintheconcretestructureoftheconstringencysew.2.TheSuconstringencycrackandpreventionSuconstringencyistheconcreteisbeforecondense,surfacebecauseoflosewaterquickerbutcreationofconstringency.TheSuconstringencycrackisgeneralatdryheatorstrongwindtheweatherappear,crack'smuchpresentinginthecenterbreadth,bothendsbeinthecenterthinandthelengthbedifferent,witheachothernotcoherentappearance.Shortercrackgenerallong20-30cm,thelongercrackcanreachtoa2-3m,breadth1-5mm.Itcreationofmainreasonis:Theconcreteiseventuallyalmosthavingnostrengthorstrengthbeforethecoagulateverysmall,perhapsconcretejusteventuallycoagulatebutstrengthveryhour,besubjectedtoheatorcomparestrongwinddintofinfluence,theconcretesurfacelosewatertoleadquick,resultinthecapillarycreationbiggernegativepressbutmakeaconcretephysicalvolumesharplyconstringency,butatthistimethestrengthofconcreteagaincan'tresistitsconstringency,thereforecreationcracked.TheinfluenceconcreteSuconstringencyopenthemainfactorofcracktohavewaterashratio,concreteofcondensetime,environmenttemperature,windvelocity,relativehumidityetc..Mainpreventionmeasure:OneischoosetousestemtheshrinkvaluesmallerhigherPortlandcementoftheearlierperiodstrengthorcommonthePortlandcementbrinemire.Twoisstrictthecontrolwaterashratio,theChanaddtoefficientlyreducewatertoincrementthecollapseofconcretefalladegreeandwitheasy,decreasecementandwaterofdosage.Threeistosprinklebeforebuildingconcrete,waterbasiclevelandtemplateeventosoakthrough.Fourisintimetooverlaytheperhapsdampgrassmatoftheplasticsthinfilm,hempsliceetc.,keepconcreteeventuallybeforethecoagulatesurfaceismoist,perhapsspraytoprotectetc.tocarryonprotectintheconcretesurface.Fiveisintheheatandstrongwindtheweathertowanttoestablishtohidesunandblockbreezefacilities,protectintime.3.SinktosinkcrackandpreventionThecreationwhichsinktosinkcrackisbecauseofthestructurefoundationsoilqualitynotandevenly,loosesoftorreturntofillsoildishonestorsoakinwaterbutresultintheasymmetrysinktodeclinewiththeresultthat;Perhapsbecauseoftemplatejustdegreeshortage,thetemplateproppeduptooncebeapartfrombigorpropupbottomloosemoveetc.tocause,especiallyatwinter,thetemplatepropupatjellysoilup,jellythesoilturnjellyempresscreationasymmetrytosinktodeclineandcauseconcretestructurecreationcrack.Thiskindcrackmanyisdeepenterorpiercethroughsexcrack,italignmenthavesomethingtodowithsinkingtosinkacircumstance,generalfollowwithgroundperpendicularorpresent30°s-45°Capedirectiondevelopment,biggersinktosinkcrack,usuallyhavecertainofwrong,crackwidthusuallywithsinktodeclinequantitydirectproportionrelation.Crackwidthundertheinfluenceoftemperaturevarietysmaller.Thefoundationaftertransformstabilitysinktosinkcrackalsobasictendinstability.Mainpreventionmeasure:Oneisrightnessloosesoftsoil,returntofillsoilfoundationaconstructionattheupperpartstructurefrontshouldcarryonnecessityofHangsolidwithreinforce.Twoisthestrengththatassurancetemplateisenoughandjustdegree,andpropupfirm,andmakethefoundationbesubjectedtodinteven.Threeiskeepconcretefromsprinkleinfusingthefoundationintheprocessissoakbywater.Fouristimethattemplatetoredowntocan'tbetooearly,andwanttonoticetodismantleamoldorderofsequence.Fiveisatjellysoiltoptaketoestablishtemplatetonoticetoadoptcertainofpreventionmeasure.4.TemperaturecrackandpreventionTemperaturecrackmuchtheoccurrenceisinbigsurfaceordifferenceintemperaturevarietyofthephysicalvolumeconcretecomparetheearthareaoftheconcretestructure.Concreteaftersprinklingtobuild,inthehardeningtheprocess,cementwaterturnacreationagreatdealofwaterturnhot,.(bethecementdosageisinthe350-550kg/m3,eachsignsquarethericeconcretewillreleaseacaloriesof17500-27500kJandmakeconcreteinternalthusthetemperaturerisetoreachto70℃orsoevenhigher)Becausethephysicalvolumeofconcretebemorebig,agreatdealofwaterturnhotaccumulateattheconcreteinnerpartbutnoteasysendforth,causeinnerpartthetemperaturehock,buttheconcretesurfacespreadhotmorequick,soformationinsideoutsideofbiggerdifferenceintemperature,thebiggerdifferenceintemperatureresultininnerpartandexteriorhotthedegreeofthebulgecoldshrinkThealignmentofthetemperaturecrackusuallynonesettleregulation,bigareastructurethecrackoftenmaneuverinterleave;Thesizebiggerstructureofthebeamplanklength,thecrackrunparallelwithshortsidemore;Thoroughwithpiercethroughsexoftemperaturecrackgeneralandshortsidedirectionparallelismorcloseparallelism,crackalonglongsidecentthesegmentappear,inthecentermoreairtight.Crackwidththesizebedifferent,besubjectedtotemperaturevarietyinfluencemoreobvious,wintercomparebreadth,summermorenarrow.Theconcretetemperaturecrackthattheheatinflationcauseisusuallyinthecenterthethickbothendsbethin,butcoldshrinkcrackofthickthinvarietynottooobvious.Theemergenceofthethiskindcrackwillcausetherusteclipseofreinforcingbar,thecarbonizationofconcrete,theanti-jellywhichlowerconcretemelt,anti-tiredandanti-extendabilityetc..Mainpreventionmeasure:Oneisasfaraspossiblechoosetouselowhotormediumhotwatermire,likemineralresiduecement,powderashfromstovecementetc.Twoisadecreasecementdosage,cementdosageasfaraspossiblethecontrolisinthe450kg/m3following.Threeistolowerwaterashratio,waterashofthegeneralconcreteratiocontrolbelow0.6.Fourisimprovementtheboneanticipateclasstogotogetherwith,theChanaddpowderashfromstoveorefficientlyreducewateretc.tocometoreducecementdosageandlowerwatertoturnhot.Fiveisanimprovementconcreteofmixblendtoprocessacraft,lowersprinkleofconcretetobuildtemperature.SixistheinadditionthattheChanaddahaveoffixedamounttoreducewaterandincreaseSu,slowcoagulateetc.functionintheconcrete,improvementtheconcretemixtomatchathingofmobility,protectwater,lowerwatertoturnhot,postponethermalspikeofemergencetime.Sevenistheheatseasonsprinkletobuildcantheadoptiontaketoestablishtohidesunplanketc.assistancemeasurecontrolconcreteoftemperaturerise,lowertosprinkletemperatureofbuildtheconcrete.Eightisthetemperatureofbigphysicalvolumeconcreteshouldthedintrelatetostructuresize,concretestructuresizemorebig,temperatureshoulddintmorebig,sowantreasonablearrangementconstructionworkpreface,layering,centthepiecesprinkletobuild,fortheconvenienceofinspreadhot,letupcontrol.Nineisatgreatinnerpartconstitutionofthephysicalvolumeconcretecooloffpiping,coldwaterperhapscoldaircooloff,letupconcreteofinsideoutsidedifferenceintemperature.Tenisthesupervisionwhichstrengthenconcretetemperature,adopttocooloffintime,protectionmeasure.11istoreservetemperatureconstringencytosew.12istoletuptocontrol,sprinkleproperbeforebuildingconcreteinthepitchrockandoldconcretetopbuilda5mmorsosandmatalayerorusageasphaltetc.materialTu2Shua.13istostrengthenconcretetoprotect,theconcreteaftersprinklebuildusemoiststrawintime,hempslice'setc.overlay,andattentionsprinklewatertoprotect,appropriateextensionprotecttime,assurancetheconcretesurfacebeslow-movingcooloff.Atthecoldseason,concretesurfaceshouldconstitutionheatpreservationmeasure,inordertopreventcoldwaveassault.14istheallocationbealittleamountintheconcreteofreinforcingbarperhapsaddfibermaterialconcreteoftemperaturecrackcontrolatcertainofscopeinside.ConclusionThecrackiswidespreadintheconcretestructureexistenceofakindofphenomenon,itofemergencenotonlywilllowertheanti-extendofbuildingability,influencebuildingofusagefunction,andwillcausetherusteclipseofreinforcingbar,thecarbonizationofconcrete,lowerthedurableofmaterial,influencebuildingofloadingability,sowanttocarryontotheconcretecrackearnestresearch,differentiationtreat,adoptionreasonableofthemethodcarryonprocessing,andatunderconstructionadoptvariousvalidofpreventionmeasuretopreventioncrackofemergenceanddevelopment,assurancebuildingandGoupiecesafety,stabilitywork.建筑施工混凝土裂縫的預防與處理迪默斯M《加拿大土木工程學報》摘要：混凝土的裂縫問題是一個普遍存在而又難于解決的工程實際問題，本文對混凝土工程中常見的一些裂縫問題進行了探討分析，并針對具體情況提出了一些預防、處理措施。關鍵詞：混凝土裂縫預防處理前言混凝土是一種由砂石骨料、水泥、水及其他外加材料混合而形成的非均質脆性材料。由于混凝土施工和本身變形、約束等一系列問題，硬化成型的混凝土中存在著眾多的微孔隙、氣穴和微裂縫，正是由于這些初始缺陷的存在才使混凝土呈現出一些非均質的特性。微裂縫通常是一種無害裂縫，對混凝土的承重、防滲及其他一些使用功能不產生危害。但是在混凝土受到荷載、溫差等作用之后，微裂縫就會不斷的擴展和連通，最終形成我們肉眼可見的宏觀裂縫，也就是混凝土工程中常說的裂縫。混凝土建筑和構件通常都是帶縫工作的，由于裂縫的存在和開展通常會使內部的鋼筋等材料產生腐蝕，降低鋼筋混凝土材料的承載能力、耐久性及抗滲能力，影響建筑物的外觀、使用壽命，嚴重者將會威脅到人們的生命和財產平安。很多工程的失事都是由于裂縫的不穩定開展所致。近代科學研究和大量的混凝土工程實踐證明，在混凝土工程中裂縫問題是不可防止的，在一定的范圍內也是可以接受的，只是要采取有效的措施將其危害程度控制在一定的范圍之內。鋼筋混凝土標準也明確規定：有些結構在所處的不同條件下，允許存在一定寬度的裂縫。但在施工中應盡量采取有效措施控制裂縫產生，使結構盡可能不出現裂縫或盡量減少裂縫的數量和寬度，尤其要盡量防止有害裂縫的出現，從而確保工程質量。混凝土裂縫產生的原因很多，有變形引起的裂縫：如溫度變化、收縮、膨脹、不均勻沉陷等原因引起的裂縫；有外載作用引起的裂縫；有養護環境不當和化學作用引起的裂縫等等。在實際工程中要區別對待，根據實際情況解決問題。混凝土工程中常見裂縫及預防:之間，大體積混凝土中平面部位多見，較薄的梁板中多沿其短向分布。干縮裂縫通常會影響混凝土的抗滲性，引起鋼筋的銹蝕影響混凝土的耐久性，在水壓力的作用下會產生水力劈裂影響混凝土的承載力等等。混凝土干縮主要和混凝土的水灰比、水泥的成分、水泥的用量、集料的性質和用量、外加劑的用量等有關。主要預防措施：一是選用收縮量較小的水泥，一般采用中低熱水泥和粉煤灰水泥，降低水泥的用量。二是混凝土的干縮受水灰比的影響較大，水灰比越大，干縮越大，因此在混凝土配合比設計中應盡量控制好水灰比的選用，同時摻加適宜的減水劑。三是嚴格控制混凝土攪拌和施工中的配合比，混凝土的用水量絕對不能大于配合比設計所給定的用水量。四是加強混凝土的早期養護，并適當延長混凝土的養護時間。冬季施工時要適當延長混凝土保溫覆蓋時間，并涂刷養護劑養護。五是在混凝土結構中設置適宜的收縮縫。塑性收縮是指混凝土在凝結之前，外表因失水較快而產生的收縮。塑性收縮裂縫一般在干熱或大風天氣出現，裂縫多呈中間寬、兩端細且長短不一，互不連貫狀態。較短的裂縫一般長20-30cm，較長的裂縫可達2-3m，寬1-5mm.其產生的主要原因為：混凝土在終