土木工程专业外文文献及翻译

学校代码:外文文献及翻译,题目About Bui di ngon theStructure Desi gn学生姓名Q学院土木工程学院一系别建筑工程系.专业土木工程（建筑工程方向）年一■—■I__・—英文原文:Building constructionconcrete crack ofprevention andprocessingAbstractThe crackproblem of concrete is a widespreadexistence butagain difficultin solveofengineering actualproblem,this textcarried ona studyanalysis toa little bit familiarcrackproblem in the concrete engineering,and aimat concretethe the heat inflationcause is usuallyin the center thethick both ends bethin,but coldSuo crack ofthick thinvariety nottoo emergence of thethis kind crack will cause therust eclipse of reinforcing bar,the carbonizationof concrete,the anti-jelly whichlowerconcrete melt,anti-tired and anti-Shen abilityetc..and preventionthat thechemical reactioncauseAlkali bonesanticipating the crack thatreaction crack and reinforcing bar rusteclipsecauseis the mostfamiliar in the reinforcedconcrete structure of because ofchemical reactionbut cause of crack.The concreteblend afuture reunioncreation somealkalescence ion,these ionwithsome activitythe boneanticipate creationchemical reactionand absorbsurroundingsenvironment inof waterbut the physical volumeenlarge,make concretecrisploose,inflation openthis kind of crack general emergenceconcrete structureusageperiod,once appearvery difficultremediable,so shouldat under construction adoptvalidthe measurecarry onof prevention measure:While beingto choose to anticipatewiththe alkaliactivity smallfreestone is the in addition which choose to use lowlye mirewithlow alkalior haveno isthe Chanwhichchoose to useaccommodation withanticipateto repressan alkalibone toanticipate reaction.Because the concrete sprinkle to build,flap Daobad perhaps is a reinforcingbar protectionlayer thinner,the harmfulmaterial getinto concrete to makereinforcingbar creationrust eclipse,the reinforcingbar physical volume of the rust eclipse inflation,cause concretebulge crack,the crack of this kind typemuch is a cracklengthways,follow theposition of reinforcingbarof preventmeasure fromhave:One is assurancereinforcing barprotection thethickness of the is a concreteclass togo togetherwith towantisa concretetosprinkle tonote andflap Daoairtight isareinforcingbar surfacelayerTu2Shua antisepsiscoating.Crack processingTheemergenceof the cracknot onlywould influencestructure ofwhole withjustdegree,return willcause therust eclipseof reinforcingbar,acceleration concrete ofcarbonization,lower durableand anti-of concretetired,anti-Shen accordingto thepropertyof crack and concretecircumstance wewant differentiation to treat,in timeprocessing,with assurance building ofsafety usage.The repairmeasure of the concretecrack ismain tohave the following somemethod:Surface repair method,infuse syrup,the Qiansew method,the structurereinforce a method,concrete displacementmethod,electricity chemistry protectionmethod andimitate to living from heal method.Surface repairthe methodbe a kind ofsimple,familiar ofrepairmethod,itmain be applicable tostability andto structureloading theability donthave the surfacecrack of influence anddeep entercrackofprocessing measurethat isusually isa surfacein crack dauberycement syrup,the wreathoxygen gum mire orat concrete surface Tu2Shua paint,asphalt etc.antisepsis material,at protectionof in the meantimefor keepingconcretefrom continueunder the influence ofvarious functionto opencrack,usuallycan adoptionthesurfaceincrackglue tostick glassfiber clothetc.measure.1,infuse syrup,the Qiansew methodInfusea syrupmethod main the concretecrack beenapplicable tohave influenceorhave alreadydefend Shenrequest to the structurewhole ofrepair,it ismake useofpressure equipmentsgum knotthe materialpress intothe crackof concrete,gum knotthematerial hardenbehind andconcrete formationone bewhole,thus reinforceof incommon use gumknot materialhas thecement thesyrup,epoxy,A JiC Xisour esterandgather ammoniaester toequalize tolearn material.The Qiansew a method isthat the crack be a kind of mostin common usemethod in,it usuallyis followthe crackdig slot,the Qianfill Suin theslot orrigid watermaterialwith attainclosing crackof incommon useSu materialhas PVCgummire,plastics ointment,the DJi rubberetc.;ln common use rigidwater materialisthepolymercement sand syrup.2,the structurereinforcea methodWhen the crack influencearrive concrete structureof function,will considerationadoptto reinforceamethodto carryon processingtothe concrete structurereinforcemedium incommonusemain havethefollowinga fewmethod:The pieceofenlargement concretestructure inevery aspectaccumulate,outside theCapedepartment of the Goupiece packtype steel,adoption prepareshould thedint methodreinforce,glue tostick steelplate toreinforce,increase toestablish fulcrumto reinforceandjet the concrete compensationreinforce.3,concrete displacementmethodConcrete displacementmethod isprocessing severitydamage concrete of akind ofvalidmethod,this methodbe firstwill damageof the concrete pickand getrid of,then againdisplacementgo intonew of concrete orother incommonusedisplacement materialhave:Common concreteor thecement sandsyrup,polymer orchange sexpolymerconcrete orsandsyrup.4,the electricitychemistry protectionmethodThe electricitychemistry antisepsisis tomake useof inflictionelectric fieldin liethequality ofelectricity chemicaleffect,change concreteor reinforcedconcrete theenvironmentappearance of the place,the bluntnessturn reinforcingbar toattain thepurposeof protectionmethod,chlorine saltswithdrawing amethod,alkalescence torecoveramethod isachemistryprotectionmethod inthree kindsofincommonusebutvalid advantageof thiskind ofmethodisa protectionmethod under the influence ofenvironment factorsmaller,apply reinforcingbar,concrete oflong-term antisepsis,since canused forcrack structurealready canalso usedfor newset upstructure.5,imitate toliving fromlegal moreImitatetolivingfromhealthe methodbeakind ofnew cracktreatment,its mimicrylivingcreature organizationsecrete acertain materialtowards sufferingwound partauto,but make the woundpart healoffunction,join someand specialcompositionsuchas containto glueknot of the liquidXin fiberor capsulein the concreteof the traditionthe composition,at concrete inner partformation theintelligence typeimitate tolivingfrom healnerve networksystem,be the concrete appear crack secretea partsof liquidXinfiber canmake the crack re-heal.ConclusionThe crack is widespreadin the concretestructureexistence of akindofphenomenon,it ofemergence notonly willlower theanti-Shen ofbuilding ability,influence buildingof usagefunction,and willcause therusteclipseof reinforcingbar,the carbonizationof concrete,lower thedurable ofmaterial,influence buildingofloading ability,so want to carryontothe concretecrack earnestresearch,differentiation treat,adoption reasonableof themethod carryon processing,and atunderconstruction adoptvarious valid of preventionmeasure toprevention crackofemergence and development,assurancebuildingand Goupiece safety,stability work.《》中From CANADIANJOURNAL OFCIVIL ENGINEERING文原文建筑施工混凝土裂缝日勺防止与处理混凝土的裂缝问题是一种普遍存在而又难于处理的工程实际问题，本文对混凝土工程中常见的某些裂缝问题进行了探讨分析，并针对详细状况提出了某些防止、处理措施关键词混凝土裂缝防止处理序言混凝土是一种由砂石骨料、水泥、水及其他外加材料混合而形成的非均质脆性材料由于混凝土施工和自身变形、约束等一系列问题，硬化成型的混凝土中存在着众多的微孔隙、气穴和微裂缝，正是由于这些初始缺陷的存在才使混凝土展现出某些非均质的特性微裂缝一般是一种无害裂缝，对混凝土的承重、防渗及其他某些使用功能不产生危害不过在混凝土受到荷载、温差等作用之后，微裂缝就会不停的扩展和连通，最终形成我们肉眼可见的宏观裂缝，也就是混凝土工程中常说的I裂缝混凝土建筑和构件一般都是带缝工作的，由于裂缝的存在和发展一般会使内部的钢筋等材料产生腐蚀,减少钢筋混凝土材料的承载能力、耐久性及抗渗能力,影响建筑物的外观、使用寿命，严重者将会威胁到人们的生命和财产安全诸多工程的失事都是由于裂缝的不稳定发展所致近代科学研究和大量的混凝土工程实践证明，在混凝土工程中裂缝问题是不可防止的I,在一定的范围内也是可以接受的，只是要采用有效的措施将其危害程度控制在一定的范围之内钢筋混凝土规范也明确规定有些构造在所处的不一样条件下，容许存在一定宽度的裂缝但在施工中应尽量采用有效措施控制裂缝产生，使构造尽量不出现裂缝或尽量减少裂缝的数量和宽度，尤其要尽量防止有害裂缝的出现，从而保证工程质量混凝土裂缝产生的原因诸多，有变形引起的裂缝如温度变化、收缩、膨胀、不均匀沉陷等原因引起的裂缝；有外载作用引起的裂缝；有养护环境不妥和化学作用引起的裂缝等等在实际工程中要区别看待，根据实际状况处理问题混凝土工程中常见裂缝及防止

1.干缩裂缝及防止干缩裂缝多出目前混凝土养护结束后的一段时间或是混凝土浇筑完毕后的一周左右水泥浆中水分的蒸发会产生干缩，且这种收缩是不可逆的干缩裂缝的产生重要是由于混凝土内外水分蒸发程度不一样而导致变形不一样的成果混凝土受外部条件的影响，表面水分损失过快，变形较大，内部湿度变化较小变形较小，较大日勺表面干缩变形受到混凝土内部约束，产生较大拉应力而产生裂缝相对湿度越低，水泥浆体干缩越大，干缩裂缝越易产生干缩裂缝多为表面性的平行线状或网状浅细裂缝，宽度多在之间，大体积混凝土中平面部位多见，较薄的梁板中多沿其短向分布干缩裂缝一般会影响混凝土的抗渗性，引起钢筋的锈蚀影响混凝土的耐久性，在水压力的作用下会产生水力劈裂影响混凝土的承载力等等混凝土干缩重要和混凝土的水灰比、水泥的成分、水泥的I用量、集料的性质和用量、外加剂的用量等有关重要防止措施一是选用收缩量较小的水泥，一般采用中低热水泥和粉煤灰水泥，减少水泥的用量二是混凝土的干缩受水灰比的影响较大，水灰比越大，干缩越大，因此在混凝土配合比设计中应尽量控制好水灰比的选用，同步掺加合适时减水剂三是严格控制混凝土搅拌和施工中的配合比，混凝土的用水量绝对不能不小于配合比设计所给定时用水量四是加强混凝土的初期养护，并合适延长混凝土的I养护时间冬季施工时要合适延长混凝土保温覆盖时间，并涂刷养护剂养护五是在混凝土构造中设置合适的I收缩缝

2.塑性收缩裂缝及防止塑性收缩是指混凝土在凝结之前，表面因失水较快而产生的收缩塑性收缩裂缝一般在干热或大风天气出现，裂缝多呈中间宽、两端细且长短不一，互不连贯状态较短的I裂缝一般长20-30cm,较长的裂缝可达2-3m,宽1-5nlm.其产生日勺重要原由于混凝土在终凝前几乎没有强度或强度很小，或者混凝土刚刚终凝而强度很小时，受高温或较大风力的影响，混凝土表面失水过快，导致毛细管中产生较大的负压而使混凝土体积急剧收缩，而此时混凝土的强度又无法抵御其自身收缩，因此产生龟裂影响混凝土塑性收缩开裂的重要原因有水灰比、混凝土的凝结时间、环境温度、风速、相对湿度等等重要防止措施一是选用干缩值较小初期强度较高的硅酸盐或一般硅酸盐水泥二是严格控制水灰比，掺加高效减水剂来增长混凝土的坍落度和和易性，减少水泥及水的用量三是浇筑混凝土之前，将基层和模板浇水均匀湿透四是及时覆盖塑料薄膜或者潮湿的草垫、麻片等，保持混凝土终凝前表面湿润，或者在混凝土表面喷洒养护剂等进行养护五是在高温和大风天气要设置遮阳和挡风设施，及时养护

3.沉陷裂缝及防止沉陷裂缝的产生是由于构造地基土质不匀、松软或回填土不实或浸水而导致不均匀沉降所致；或者由于模板刚度局限性，模板支撑间距过大或支撑底部松动等导致，尤其是在冬季，模板支撑在冻土上，冻土化冻后产生不均匀沉降，致使混凝土构造产生裂缝此类裂缝多为深进或贯穿性裂缝，其走向与沉陷状况有关,一般沿与地面垂直或呈30°-45°角方向发展，较大的沉陷裂缝，往往有一定时错位，裂缝宽度往往与沉降量成正比关系裂缝宽度受温度变化的影响较小地基变形稳定之后，沉陷裂缝也基本趋于稳定重要防止措施一是对松软土、回填土地基在上部构造施工前应进行必要的扎实和加固二是保证模板有足够的强度和刚度，且支撑牢固，并使地基受力均匀三是防止混凝土浇灌过程中地基被水浸泡四是模板拆除的时间不能太早，且要注意拆模的先后次序五是在冻土上搭设模板时要注意采用一定的防止措施

4.温度裂缝及防止温度裂缝多发生在大体积混凝土表面或温差变化较大地区的混凝土构造中混凝土浇筑后，在硬化过程中，水泥水化产生大量的水化热，（当水泥用量在350-550kg/m3,每立方米混凝土将释放出kJ的热量，从而使混凝土内部温度升达70℃左右甚至更高）由于混凝土的J体积较大，大量的水化热聚积在混凝土内部而不易散发，导致内部温度急剧上升，而混凝土表面散热较快，这样就形成内circumstance putforward someprevention,processing measure.Keyword:Concrete crackprevention processingForewordConcretesising1kind isanticipate bythe freestonebone,cement,water andothermixture butformation of theinaddition materialof qualitybrittleness not and alltheconcrete constructiontransform withoneself,control etc.a seriesproblem,hardenmodel ofin theconcrete existencenumerous tinyhole,spirit caveand tiny crack,isexactly becausethese beginningstart blemishof existencejust makethe concretepresentone somenot andall thecharacteristic oftiny crack isakindofharmless crackandaccept concreteheavy,defend Shenandalittlebitother usefunction nota creationtoafter theconcrete be subjected tolotus carry,difference in temperature etc.function,tinycrackwould continuouslyof expandwith connect,end formationwe canseewithout theaid ofinstruments ofmacro viewthe crackbe alsothecrack that theconcreteoften sayin theengineering.Concrete buildingand Goupiece usuallyall takesewer tomake of,because ofcrackof existenceanddevelopmentusually makeinner partofreinforcingbar etc.material creationdecay,lower reinforcedconcrete materialof loadingability,durable外的较大温and anti-Shen ability,influence buildingof externalappearance,service life,差，较大的温差导致内部与外部热胀冷缩日勺程度不一样，使混凝土表面产生一定日勺拉应力当拉应力超过混凝土的抗拉强度极限时，混凝土表面就会产生裂缝，这种裂缝多发生在混凝土施工中后期在混凝土的施工中当温差变化较大，或者是混凝土受到寒潮的袭击等，会导致混凝土表面温度急剧下降，而产生收缩，表面收缩的I混凝土受内部混凝土的约束，将产生很大的拉应力而产生裂缝，这种裂缝一般只在混凝土表面较浅的范围内产生温度裂缝的走向一般无一定规律，大面积构造裂缝常纵横交错；梁板类长度尺寸较大的构造，裂缝多平行于短边；深入和贯穿性的温度裂缝一般与短边方向平行或靠近平行，裂缝沿着长边分段出现，中间较密裂缝宽度大小不一，受温度变化影响较为明显，冬季较宽，夏季较窄高温膨胀引起的混凝土温度裂缝是一般中间粗两端细，而冷缩裂缝欧I粗细变化不太明显此种裂缝的出现会引起钢筋的I锈蚀，混凝土的碳化，减少混凝土的抗冻融、抗疲劳及抗渗能力等重要防止措施一是尽量选用低热或中热水泥，如矿渣水泥、粉煤灰水泥等二是减少水泥用量，将水泥用量尽量控制在450kg/m3如下三是减少水灰比，一般混凝土的水灰比控制在如下四是改善骨料级配，掺加粉煤灰或高效减水剂等来减少水泥用量，减少水化热五是改善混凝土的搅拌加工工艺，减少混凝土的浇筑温度六是在混凝土中掺加一定量的具有减水、增塑、缓凝等作用的I外加剂,改善混凝土拌合物日勺流动性、保水性，减少水化热，推迟热峰时出现时间七是高温季节浇筑时可以采用搭设遮阳板等辅助措施控制混凝土的温升，减少浇筑混凝土的温度八是大体积混凝土的温度应力与构造尺寸有关，混凝土构造尺寸越大，温度应力越大，因此要合理安排施工工序，分层、分块浇筑，以利于散热，减小约束九是在大体积混凝土内部设置冷却管道，通冷水或者冷气冷却，减小混凝土的内外温差十是加强混凝土温度的监控，及时采用冷却、保护措施十一是预留温度收缩缝十二是减小约束，浇筑混凝土前宜在基岩和老混凝土上铺设51nm左右的砂垫层或使用沥青等材料涂刷十三是加强混凝土养护，混凝土浇筑后，及时用湿润的草帘、麻片等覆盖，并注意洒水养护，合适延长养护时间，保证混凝土表面缓慢冷却在寒冷季节，混凝土表面应设置保温措施，以防止寒潮袭击十四是混凝土中配置少许的钢筋或者掺入纤维材料将混凝土的温度裂缝控制在一定日勺范围之内

5.化学反应引起的裂缝及防止碱骨料反应裂缝和钢筋锈蚀引起的裂缝是钢筋混凝土构造中最常见的I由于化学反应而引起的裂缝混凝土拌和后会产生某些碱性离子，这些离子与某些活性骨料产生化学反应并吸取周围环境中日勺水而体积增大，导致混凝土酥松、膨胀开裂这种裂缝一般出现中混凝土构造有效期间，一旦出现很难补救，因此应在施工中采用有效措施进行防止重要的I防止措施一是选用碱活性小时砂石骨料二是选用低碱水泥和低碱或无碱的I外加剂三是选用合适日勺掺和料克制碱骨料反应由于混凝土浇筑、振捣不良或者是钢筋保护层较薄，有害物质进入混凝土使钢筋产生锈蚀，锈蚀的钢筋体积膨胀，导致混凝土胀裂，此种类型的裂缝多为纵向裂缝，沿钢筋的位置出现一般的防止措施有一是保证钢筋保护层的厚度二是混凝土级配要良好三是混凝土浇注要振捣密实四是钢筋表层涂刷防腐涂料裂缝处理裂缝的I出现不仅会影响构造日勺整体性和刚度，还会引起钢筋的锈蚀、加速混凝土的碳化、减少混凝土的耐久性和抗疲劳、抗渗能力因此根据裂缝的性质和详细状况我们要区别看待、及时处理，以保证建筑物的安全使用混凝土裂缝的修补措施重要有如下某些措施表面修补法，灌浆、嵌缝封堵法，构造加固法，混凝土置换法，电化学防护法以及仿生自愈合法表面修补法是一种简朴、常见的修补措施，它重要合用于稳定和对构造承载能力没有影响的表面裂缝以及深进裂缝的处理一般的处理措施是在裂缝的表面涂抹水泥浆、环氧胶泥或在混凝土表面涂刷油漆、沥青等防腐材料，在防护的同步为了防止混凝土受多种作用的影响继续开裂，一般可以采用在裂缝时表面粘贴玻璃纤维布等措施

1、灌浆、嵌缝封堵法灌浆法重要合用于对构造整体性有影响或有防渗规定的混凝土裂缝的I修补,它是运用压力设备将胶结材料压入混凝土的裂缝中，胶结材料硬化后与混凝土形成一种整体，从而起到封堵加固的目的常用的胶结材料有水泥浆、环氧树脂、甲基丙烯酸酯、聚氨酯等化学材料嵌缝法是裂缝封堵中最常用的一种措施，它一般是沿裂缝凿槽，在槽中嵌填塑性或刚性止水材料，以到达封闭裂缝的目的常用口勺塑性材料有聚氯乙烯胶泥、塑料油膏、丁基橡胶等等；常用的刚性止水材料为聚合物水泥砂浆

2、构造加固法当裂缝影响到混凝土构造的性能时，就要考虑采用加固法对混凝土构造进行处理构造加固中常用的重要有如下几种措施加大混凝土构造的截面面积，在构件欧I角部外包型钢、采用预应力法加固、粘贴钢板加固、增设支点加固以及喷射混凝土补强加固

3、混凝土置换法混凝土置换法是处理严重损坏混凝土的一种有效措施，此措施是先将损坏的混凝土剔除，然后再置换入新的混凝土或其他材料常用的置换材料有一般混凝土或水泥砂浆、聚合物或改性聚合物混凝土或砂浆

4、电化学防护法电化学防腐是运用施加电场在介质中日勺电化学作用，变化混凝土或钢筋混凝土所处的I环境状态，钝化钢筋，以到达防腐的目日勺阴极防护法、氯盐提取法、碱性复原法是化学防护法中常用而有效的三种措施这种措施的长处是防护措施受环境原因的影响较小，合用钢筋、混凝土的长期防腐，既可用于已裂构造也可用于新建构造

5、仿生自愈合法仿生自愈合法是一种新的裂缝处理措施，它模仿生物组织对受创伤部位自动分泌某种物质，而使创伤部位得到愈合的机能，在混凝土的老式成分中加入某些特殊成分（如含粘结剂的液芯纤维或胶囊），在混凝土内部形成智能型仿生自愈合神经网络系统，当混凝土出现裂缝时分泌出部分液芯纤维可使裂缝重新愈合结论裂缝是混凝土构造中普遍存在的一种现象，它的出现不仅会减少建筑物的抗渗能力，影响建筑物的使用功能，并且会引起钢筋的锈蚀，混凝土的碳化，减少材料的耐久性，影响建筑物的承载能力，因此要对混凝土裂缝进行认真研究、区别看待，采用合理的措施进行处理，并在施工中采用多种有效的防止措施来防止裂缝欧I出现和发展，保证建筑物和构件安全、稳定地工作出自《加拿大土木工程学报》severity willthreat arrivepeoples lifeand propertylot ofall ofcrash ofengineerings isbecause oftheunsteady developmentofthecrack withthe resultage scienceresearchwith a great deal of oftheconcreteengineering practicecertificate,in theconcreteengineering crackproblem is ineluctable,also acceptablein certainlyofthescope justneedto adoptvalidofmeasure willit endangerdegree controlat certain of scopereinforcedconcrete normis alsoexplicit provision:Some structureat placeofdissimilarity under the conditionallow existencecertain thecrackofat underconstructionshould as far as possible adopta validmeasure controlcrack creation,makethe structure dontappearcrackpossibly orasfar aspossibledecrease crackofamount andwidth,particularly wantto asfar aspossible avoidharmful crackofemergence,insure engineeringquality thus.Concrete crackcreation ofthe reasonbealot ofand havealready transformedtocause of crack:Such astemperature variety,constringency,inflation,the asymmetrysinkto sinketc.reason causeof crack;Have outsidecarry thecrack that the functioncause;Protected environmentnot appropriatethecracketc.caused withchemicaldifferentiation totreat inthe actualengineering,work°out aproblem accordingto theactualcircumstance.In theconcreteengineeringthe familiarcrack andthe preventionSuo crack andpreventionStem the Suo crackmuch appearafter theconcrete protectbe overofaperiod oftimeor concretesprinkleto build tocomplete behindof arounda thecement syruphumidityof evaporatewould creationstem Suo,and thiskindofconstringency iscantSuo crackofthecreation be main isbecauseof concrete inside outside humidityevaporatedegree dissimilaritybut causeto transformdissimilarity ofresult:Theconcrete issubjected toexterior conditionof influence,surface humidityloss leadquick,transform bigger,inner partdegree ofhumidity varietysmaller transformsmaller,biggersurface stem the Suotransform to be subjected to concreteinner partcontrol,creationmore bigpull should dint but creation relative humidity ismore low,cement syrupbodystem Suomore big,stem the Suo crackbe moreeasy theSuocrackis muchsurfaceparallel linesform orthe netshallow thincrack,width manybetween mm,the flatsurfacepart muchsee inthe bigphysical volume concrete andfollow itmore inthinnerbeam plankshort toSuocrack usually theanti-Shen of influence concrete,cause thedurableoftherusteclipseinfluence concreteofreinforcingbar,underthefunction ofthewater pressuredint wouldcreation thewater powersplit crackinfluence concreteofloading dintetc..Concrete stemtheSuo bemainwith water ash oftheconcreteratio,the dosageofthecomposition,cement ofcement,gather toanticipate ofthe dosage of thepropertyand dosage,inadditionetc.relevant.Main preventionmeasure:While beingto choosetousethe constringencyquantitysmaller cement,general lowhot watermire andpowder ashfrom stovecementintheadoption,lower thedosageof isaconcreteofstemtheSuobe subjectedto waterash ratio of influencemore big,waterash ratio more big,stem Suomorebig,soin theconcrete matchthe ratiothe designshould asfaraspossible controlgood waterash ratioofchoosetouse,the Chanadd inthe meantimeaccommodation ofreduce isstrictcontrol concretemix blendwith underconstruction ofmatch ratio,useofconcretewater quantityabsolute cantbig inmatch ratiodesign givesettle ofuse wateris theearlierperiod whichstrengthen concreteto protect,and appropriateextension protectofconcrete constructionwanttobe appropriateextension concreteheat preservationtooverlay time,and Tu2Shua protectto isa constitutionthe accommodationis intheconcrete structureoftheconstringency sew.Su constringencycrack andpreventionSu constringencyistheconcrete isbefore condense,surface becauseof losewaterquicker butcreation ofSu constringencycrackisgeneral atdry heat or strongwind the weatherappear,cracks muchpresenting inthecenterbreadth,bothendsbein thecenterthin andthe lengthbe different,with eachother notcoherent crackgenerallong20-30cm,the longercrack canreach toa2-3m,breadth1-5creation ofmainreason is:The concreteis eventuallyalmost havingno strengthor strengthbefore theNingvery small,perhaps concretejust eventuallyNing butstrength veryhour,besubjected toheatorcompare strongwind dintofinfluence,theconcrete surface losewater to leadquick,result ininthecapillary creationbigger negativepress butmake aconcretephysical volumesharply constringency,but atthis timethe strengthofconcrete againcant resistits constringency,therefore creationinfluence concreteSuconstringency openthe mainfactor ofcrack tohave waterashratio,concrete ofcondensetime,environment temperature,wind velocity,relativehumidity...etc..Main preventionmeasure:One ischoosetouse stemtheSuovalue smallerhigherHuo soursalt ofthe earlierperiod strengthor commonthe Huosour brineis strictthecontrol waterashratio,the Chanadd toefficiently reducewatertoincrement thecollapseofconcretefall adegree andwith easy,decrease cementand waterofistosprinkle beforebuilding concrete,water basiclevel andtemplate evento soakis intimeto overlaythe perhapsdamp grassmat ofthe plasticsthin film,hemp sliceetc.,keepconcrete eventuallybefore theNing surfaceis moist,perhaps sprayto protectetc.tocarry onprotect intheconcreteis intheheatand strongwindtheweather towant toestablishto hidesun andblock breezefacilities,protect intime.to sinkcrackandpreventionThe creationwhich sink to sinkcrackisbecauseofthestructurefoundation soilqualitynotandevenly,loose softor return to fillsoil dishonestor soakin waterbutresult inthe asymmetrysink to decline withthe resultthat;Perhaps becauseof templatejust degree shortage,the templatepropped upto oncebe apartfrom bigor prop upbottom loosemove etc.to cause,especially atwinter,the templatepropupat jellysoilup,jelly thesoil turnjelly empresscreation asymmetryto sinktodeclineand causeconcretestructure creationkindcrackmany isdeep enteror piercethrough sexcrack,italignment havesomething todo withsinking to sink acircumstance,general followwithground perpendicularor present30°s-45°Cape directiondevelopment,bigger sinktosink crack,usually havecertain ofwrong,crack widthusually withsinktodeclinequantity directproportion widthundertheinfluenceof temperature varietyfoundationafter transformstability sinktosinkcrack alsobasic tendin stability.Main preventionmeasure:One isrightness loosesoft soil,returntofill soilfoundationa constructionattheupper partstructure frontshould carryon necessityofHang solidwith isthe strengththat assurancetemplate isenough andjustdegree,andprop upfirm,and makethe foundationbesubjectedto dintis keepconcrete fromsprinkleinfusing thefoundation inthe processis soakby istime thattemplate toredownto cantbe tooearly,and wantto noticeto dismantlea moldorder ofis atjelly soiltoptake toestablish templateto noticeto adoptcertainofpreventionmeasure.crackandpreventionTemperature crackmuch theoccurrence isin bigsurface ordifference intemperaturevariety ofthephysicalvolumeconcretecompare theearth areaof theconcreteafter sprinklingtobuild,inthehardening theprocess,cement waterturn acreationa greatdeal ofof waterturn hot,.be thecement dosageisinthe350-550kg/m3,each signsquare therice concretewill releasea caloriesof kJand make concreteinternal thusthe temperaturerise toreach to70or soeven higherBecausethe℃physicalvolumeofconcrete be morebig,agreatdealofof waterturn hotaccumulate attheconcreteinnerpart butnot easysend forth,cause innerpart the temperature hoick,but theconcrete surfacespread hotmore quick,so formationinsideoutsideof biggerdifference in temperature,the biggerdifferenceintemperature resultin innerpart andexteriorhot thedegree ofthe bulgecold Suodissimilarity,makeconcretesurfacecreation certainof pull should pullshoulddintexceed theanti-ofconcretepull strengthextremelimit,concretesurfacemeeting creation crack,thiskindofcrackmuchoccurrence aftertheconcreteunderconstructiontheconcreteof underconstruction bedifferenceintemperaturevariety morebig,perhapsisaconcretetobesubjected toassaultof coldwave etc.,willcauseconcretesurfacethetemperaturesharply descend,butcreationconstringency,surface constringencyoftheconcretebesubjectedtoinnerpart concreteof control,creation verybig ofpullshoulddint butcreationcrack,this kindofcrackusuallyjust inmore shallowscope oftheconcretesurface creation.The alignmentofthetemperature crackusually nonesettle regulation,big areastructurethecrackoften maneuverinterleave;The sizebigger structureofthebeamplank length,thecrackrun parallelwith shortside more;Thorough withpierce throughsexoftemperaturecrackgeneraland shortside directionparallelism orclose parallelism,crack alonglong sidecent thesegment appear,inthecenter morewidth thesize bedifferent,besubjectedto temperaturevariety influencemore obvious,winter comparebreadth,summer moreconcrete temperaturecrackthat。