About Buiding on the Structure Design外文文献及翻译

About Bui di ngon theStructure Desi gn英文原文Building constructionconcrete crack ofprevention andprocessingAbstractThe crackproblem of concrete is a widespreadexistence butagain difficultin solveofengineering actualproblem,this textcarried ona studyanalysis toa littlebit familiarcrackproblem in the concrete engineering,and aimat concretethe circumstanceputforward someprevention,processing measure.Keyword:Concrete crackpreventionprocessingForewordConcretes ising1kind isanticipate bythe freestonebone,cement,water andothermixture butformation of the in addition materialof qualitybrittleness not and allmaterial.Because the concrete constructiontransform withoneself,control etc.a seriesproblem,harden modelof in the concreteexistence numeroustiny hole,spirit caveandtiny crack,is exactlybecause thesebeginning startblemish of existence justmake theconcretepresent onesome notand allthe characteristicof quality.The tinyreinforce.3,concrete displacementmethodConcrete displacementmethod isprocessing severitydamage concrete of a kind ofvalidmethod,this methodbe firstwill damageof the concrete pickand getrid of,then againdisplacementgo intonew of concrete orother material.The in common usedisplacementmaterial have:Common concrete or the cement sand syrup,polymer orchangesex polymerconcreteorsandsyrup.4,the electricity chemistry protection methodThe electricitychemistry antisepsisis to make use of inflictionelectric fieldin liethequality ofelectricity chemicaleffect,change concreteor reinforced concrete theenvironmentappearance of the place,the bluntnessturn reinforcing bar toattain thepurposeof antisepsis.Cathode protectionmethod,chlorine saltswithdrawing a method,alkalescence torecover a method isa chemistryprotectionmethodin threekinds of incommon usebut validmethod.The advantageof this kind ofmethod isa protectionmethodunder the influence ofenvironment factorsmaller,apply reinforcing bar,concrete oflong-term antisepsis,since canused forcrack structurealready canalso usedfornew setup structure.5,imitate to living fromlegal moreImitatetoliving from healthe methodbe a kind ofnew cracktreatment,its mimicrylivingcreature organizationsecrete acertain materialtowards sufferingwound partauto,but make the woundpart healof function,join someand specialcompositionsuchas containto glueknot of the liquidXin fiberor capsulein the concrete of the traditionthe composition,at concrete inner partformation the intelligence typeimitate tolivingfrom healnerve networksystem,be the concrete appear crack secretea partsof liquidXinfiber canmake the crack re-heal.ConclusionThe crack is widespreadin the concrete structureexistence of a kind ofphenomenon,it ofemergence not only willlower the anti-Shen of building ability,influence building of usagefunction,and will cause the rust eclipse of reinforcing bar,the carbonizationof concrete,lower thedurable ofmaterial,influence buildingofloading ability,so want to carry on to the concretecrack earnestresearch,differentiation treat,adoption reasonableof the method carryon processing,and atunder construction adoptvarious valid of preventionmeasure to prevention crack ofemergence and development,assurance buildingand Goupiece safety,stability work.From CANADIANJOURNAL OFCIVIL ENGINEERING》中文原文建筑施工混凝土裂缝的预防与处理混凝土的裂缝问题是一个普遍存在而又难于解决的工程实际问题，本文对混凝土工程中常见的一些裂缝问题进行了探讨分析，并针对具体情况提出了一些预防、处理措施关键词混凝土裂缝预防处理S刖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本身变形、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呈现出一些非均质的特性微裂缝通常是一种无害裂缝，对混凝土的承重、防渗及其他一些使用功能不产生危害但是在混凝土受到荷载、温差等作用之后，微裂缝就会不断的扩展和连通，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裂缝混凝土建筑和构件通常都是带缝工作的，由于裂缝的存在和发展通常会使内部的钢筋等材料产生腐蚀，降低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很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避免的，在一定的范围内也是可以接受的，只是要采取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结构在所处的不同条件下，允许存在一定宽度的裂缝但在施工中应尽量采取有效措施控制裂缝产生，使结构尽可能不出现裂缝或尽量减少裂缝的数量和宽度，尤其要尽量避免有害裂缝的出现，从而确保工程质量混凝土裂缝产生的原因很多，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；有养护环境不当和化学作用引起的裂缝等等在实际工程中要区别对待，根据实际情况解决问题混凝土工程中常见裂缝及预防

1.干缩裂缝及预防干缩裂缝多出现在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主要是由于混凝土内外水分蒸发程度不同而导致变形不同的结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,较大的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

0.05-

0.2mm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通常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主要和混凝土的水灰比、水泥的成分、水泥的用量、集料的性质和用量、外加剂的用量等有关主要预防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，降低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，同时掺加合适的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大于配合比设计所给定的用水量四是加强混凝土的早期养护，并适当延长混凝土的养护时间冬季施工时要适当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结构中设置合适的收缩缝

2.塑性收缩裂缝及预防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裂缝一般长20-30cm,较长的裂缝可达2-3m,宽1-5mm.其产生的主要原因为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，造成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抗其本身收缩，因此产生龟裂影响混凝土塑性收缩开裂的主要因素有水灰比、混凝土的凝结时间、环境温度、风速、相对湿度等等主要预防措施一是选用干缩值较小早期强度较高的硅酸盐或普通硅酸盐水泥二是严格控制水灰比，掺加高效减水剂来增加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.沉陷裂缝及预防沉陷裂缝的产生是由于结构地基土质不匀、松软或回填土不实或浸水而造成不均匀沉降所致；或者因为模板刚度不足，模板支撑间距过大或支撑底部松动等导致，特别是在冬季，模板支撑在冻土上，冻土化冻后产生不均匀沉降，致使混凝土结构产生裂缝此类裂缝多为深进或贯穿性裂缝，其走向与沉陷情况有关，一般沿与地面垂直或呈30°-45°角方向发展，较大的沉陷裂缝，往往有一定的错位，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主要预防措施一是对松软土、回填土地基在上部结构施工前应进行必要的夯实和加固二是保证模板有足够的强度和刚度，目支撑牢固，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取一定的预防措施

4.温度裂缝及预防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结构中混凝土浇筑后，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17500-27500kJ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，这样就形成内外的较大温差，较大的温差造成内部与外部热胀冷缩的程度不同，使混凝土表面产生一定的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，这种裂缝通常只在混凝土表面较浅的范围内产生温度裂缝的走向通常无一定规律，大面积结构裂缝常纵横交错；梁板类长度尺寸较大的结构，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接近平行，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通常中间粗两端细，而冷缩裂缝的粗细变化不太明显此种裂缝的出现会引起钢筋的锈蚀，混凝土的碳化，降低混凝土的抗冻融、抗疲劳及抗渗能力等主要预防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以下三是降低水灰比，一般混凝土的水灰比控制在

0.6以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，降低水化热五是改善混凝土的搅拌加工工艺，降低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、缓凝等作用的外加剂，改善混凝土拌合物的流动性、保水性，降低水化热，推迟热峰的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，降低浇筑混凝土的温度八是大体积混凝土的温度应力与结构尺寸相关，混凝土结构尺寸越大，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，及时采取冷却、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5nlm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，适当延长养护时间,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量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的范围之内

5.化学反应引起的裂缝及预防碱骨料反应裂缝和钢筋锈蚀引起的裂缝是钢筋混凝土结构中最常见的由于化学反应而引起的裂缝混凝土拌和后会产生一些碱性离子，这些离子与某些活性骨料产生化学反应并吸收周围环境中的水而体积增大，造成混凝土酥松、膨胀开裂这种裂缝一般出现中混凝土结构使用期间，一旦出现很难补救，因此应在施工中采取有效措施进行预防主要的预防措施一是选用碱活性小的砂石骨料二是选用低碱水泥和低碱或无碱的外加剂三是选用合适的掺和料抑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，沿钢筋的位置出现通常的预防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出现不但会影响结构的整体性和刚度，还会引起钢筋的锈蚀、加速混凝土的碳化、降低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具体情况我们要区别对待、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主要有以下一些方法表面修补法，灌浆、嵌缝封堵法，结构加固法，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单、常见的修补方法，它主要适用于稳定和对结构承载能力没有影响的表面裂缝以及深进裂缝的处理通常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，在防护的同时为了防止混凝土受各种作用的影响继续开裂，通常可以采用在裂缝的表面粘贴玻璃纤维布等措施

1、灌浆、嵌缝封堵法灌浆法主要适用于对结构整体性有影响或有防渗要求的混凝土裂缝的修补，它是利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个整体，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方法，它通常是沿裂缝凿槽，在槽中嵌填塑性或刚性止水材料，以达到封闭裂缝的目的常用的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、结构加固法当裂缝影响到混凝土结构的性能时，就要考虑采取加固法对混凝土结构进行处理结构加固中常用的主要有以下几种方法加大混凝土结构的截面面积，在构件的角部外包型钢、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方法，此方法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普通混凝土或水泥砂浆、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利用施加电场在介质中的电化学作用，改变混凝土或钢筋混凝土所处的环境状态，钝化钢筋，以达到防腐的目的阴极防护法、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方法这种方法的优点是防护方法受环境因素的影响较小，适用钢筋、混凝土的长期防腐，既可用于已裂结构也可用于新建结构

5、仿生自愈合法仿生自愈合法是一种新的裂缝处理方法，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，在混凝土的传统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结构中普遍存在的一种现象，它的出现不仅会降低建筑物的抗渗能力，影响建筑物的使用功能，而且会引起钢筋的锈蚀，混凝土的碳化，降低材料的耐久性，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、区别对待，采用合理的方法进行处理，并在施工中采取各种有效的预防措施来预防裂缝的出现和发展，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》crack isakind of harmlesscrack and accept concreteheavy,defend Shenanda little bitotheruse functionnotacreation toendanger.But after the concrete be subjected tolotus carry,difference in temperature etc.function,tiny crackwould continuouslyofexpand withconnect,end formationwe cansee withoutthe aidof instrumentsofmacro viewthe crack be alsothe crack that the concrete oftensay in the engineering.Concrete buildingand Goupiece usuallyall takesewer tomake of,because ofcrack ofexistenceanddevelopmentusually makeinner partof reinforcing bar etc.material creationdecay,lower reinforcedconcrete materialof loadingability,durableand anti-Shen ability,influence buildingof externalappearance,service life,severitywill threatarrive peopleslife and property safety.A lot of allof crash of engineeringsisbecause of the unsteadydevelopment of the crackwith the result that.Modern agescienceresearch witha great deal of of the concrete engineeringpractice certificate,inthe concreteengineering crackproblem is ineluctable,also acceptablein certainlyof thescopejust needto adopt validofmeasure willit endangerdegree control at certain ofscope inside.The reinforcedconcrete normis alsoexplicit provision:Some structureatplace ofdissimilarity under the conditionallow existencecertain the crackofwidth.Butat underconstruction shouldas far as possibleadopt avalid measurecontrol crackcreation,makethe structure dontappearcrackpossibly oras faras possibledecreasecrack ofamount andwidth,particularly wantto as faras possible avoidharmful crackofemergence,insure engineeringquality thus.Concrete crackcreation ofthe reasonbe alotofand have already transformedtocause of crack:Such astemperature variety,constringency,inflation,the asymmetrysinkto sinketc.reason cause of crack;Have outsidecarry the crack that the functioncause;Protected environmentnot appropriatethe cracketc.caused withchemicaleffect.Want differentiationto treatin the actual engineering,work°out aproblemaccording totheactualcircumstance.In the concreteengineeringthe familiarcrack and the preventionl.Stem Suo crack andpreventionStem the Suo crack much appearafter the concrete protectbe overofaperiod oftimeor concrete sprinkle to build tocomplete behindof arounda week.ln thecementsyrup humidityof evaporatewould creationstem Suo,and this kind ofconstringency iscantnegative.Stem Suo crackofthe creationbe mainis becauseof concreteinsideoutside humidityevaporate degreedissimilarity butcause totransform dissimilarityofresult:The concreteis subjected to exteriorcondition of influence,surface humiditylosslead quick,transform bigger,inner partdegree ofhumidity varietysmaller transformsmaller,bigger surfacestem the Suo transformto be subjected toconcrete inner partcontrol,creation more big pull should dint but creation crack.The relative humidity ismorelow,cement syrupbody stemSuo more big,stem theSuo crackbe moreeasycreation.Stem theSuocrackis muchsurface parallellines formor thenet shallowthincrack,width manybetween

0.05-

0.2mm,the flatsurface partmuch seein thebigphysical volume concrete andfollow itmore inthinner beamplank shorttodistribute.Stem Suocrack usuallythe anti-Shen ofinfluence concrete,cause thedurableof the rust eclipseinfluence concrete of reinforcingbar,under thefunction ofthe waterpressuredint wouldcreation thewater powersplit crack influence concrete of loadingdintetc..Concrete stemtheSuobe mainwith water ashofthe concrete ratio,thedosage ofthecomposition,cement ofcement,gather to anticipate ofthe dosage of thepropertyand dosage,inadditionetc.relevant.Main preventionmeasure:While beingto choose to usethe constringencyquantitysmaller cement,general lowhot watermire andpowder ash from stovecementin theadoption,lower thedosageofcement.Two isa concrete of stemthe Suobe subjected towater ash ratio ofinfluence morebig,water ashratio morebig,stemSuo morebig,so in the concretematch theratio thedesign shouldas faras possiblecontrolgood water ashratioof choose to use,the Chanadd in the meantimeaccommodationof reducewater.Three isstrict control concrete mixblend withunderconstruction ofmatch ratio,useof concrete waterquantity absolutecant bigin matchratiodesign givesettle ofuse waterquantity.Four is the earlierperiod whichstrengthenconcrete to protect,and appropriate extension protectof concretetime.Winterconstruction wantto be appropriate extensionconcrete heatpreservation to overlaytime,and Tu2Shua protectto protect.Five isa constitutionthe accommodationis in theconcrete structure oftheconstringency sew.

2.The Suconstringency crack and preventionSuconstringency is theconcreteis beforecondense,surface becauseof losewaterquicker but creation ofconstringency.The Suconstringency crackis generalat dryheator strong wind theweather appear,cracks muchpresenting in the centerbreadth,both endsbe in the centerthinandthelength be different,with eachother notcoherentappearance.Shorter crack general long20-30cm/the longercrack canreach toa2-3m,breadth1-5mm.lt creationof mainreason is:The concreteis eventuallyalmost havingnostrength orstrength beforethe Ningvery small,perhaps concretejust eventuallyNingbut strengthvery hour,be subjectedto heator comparestrongwinddint ofinfluence,theconcrete surface losewater tolead quick,result inin thecapillarycreation biggernegative pressbut makea concretephysical volumesharplyconstringency,but atthis timethe strengthof concreteagain cantresist itsconstringency,therefore creation cracked.The influenceconcrete Suconstringency openthemain factorof crackto havewater ashratio,concreteofcondense time,environment temperature,wind velocity,relativehumidity...etc..Main preventionmeasure:One ischoose to use stemtheSuovalue smallerhigherHuo soursalt ofthe earlierperiod strengthor commonthe Huosour brinemire.Two isstrictthe controlwater ashratio,the Chanadd toefficiently reducewater toincrementthe collapseof concretefall adegree andwith easy,decrease cementand waterofdosage.Three is to sprinklebefore building concrete,water basiclevel andtemplateeven tosoak through.Four isin timetooverlaythe perhapsdamp grassmat oftheplastics thinfilm,hemp sliceetc.,keep concreteeventually beforethe Ningsurface ismoist,perhaps sprayto protectetc.to carryon protect in theconcrete surface.Five isinthe heatand strongwind theweather to wanttoestablish tohide sunand blockbreezefacilities,protectin time.

3.Sink to sink crackand preventionThecreation whichsink to sink crackis becauseofthe structure foundationsoilquality notand evenly,loose softor return to fillsoil dishonestor soakin waterbutresult in the asymmetrysink todecline with theresultthat;Perhaps becauseoftemplate justdegree shortage,the templatepropped upto oncebe apartfrombig orprop upbottom loosemove etc.to cause,especially atwinter,the templatepropup at jelly soilup,jelly thesoil turnjelly empresscreation asymmetryto sinktodecline andcause concrete structure creationcrack.This kind crack manyisdeep enteror piercethrough sexcrack,it alignmenthave somethingto dowithsinking tosink acircumstance,general followwith groundperpendicular orpresent30°s-45°Cape directiondevelopment,bigger sink tosinkcrack,usuallyhave certain of wrong,crack widthusually withsinktodecline quantitydirectproportion relation.Crack widthunder theinfluence of temperature varietysmaller.The foundationafter transformstability sinktosinkcrack alsobasic tendinstability.Main preventionmeasure:One isrightness looseso代soil,returntofill soilfoundationa constructionat theupper partstructure frontshould carryon necessityofHang solidwith reinforce.Two is the strengththat assurancetemplate isenough andjustdegree,andpropup firm,and makethe foundationbesubjectedto dinteven.Three iskeepconcrete fromsprinkle infusingthe foundationintheprocess issoak bywater.Fouris timethat template tore downto cantbe tooearly,and wantto noticeto dismantleamold orderof sequence.Five isatjellysoil toptake toestablish templateto noticetoadopt certainof preventionmeasure.

4.Temperature crackand preventionTemperaturecrackmuchthe occurrenceisinbig surfaceor difference intemperature varietyofthe physical volumeconcrete comparethe eartharea oftheconcrete structure.Concrete aftersprinkling to build,inthehardening theprocess,cement water turn acreation a greatdealofof water turn hot,.be thecement dosageisinthe350-550kg/m3,each signsquare therice concretewill releasea caloriesof17500-27500kJ andmake concreteinternal thusthe temperaturerise toreach to70℃or soeven higherBecause thephysical volume of concrete bemorebig,agreatdeal ofofwaterturnhot accumulateattheconcreteinner part butnot easysend forth,causeinner partthe temperaturehoick,but theconcretesurfacespread hotmore quick,soformation insideoutside ofbigger differencein temperature,the biggerdifferenceintemperatureresult ininner partand exteriorhot thedegree ofthe bulgecold Suodissimilarity,make concretesurface creationcertainofpull shoulddint.When pullshoulddint exceedthe anti-ofconcretepull strengthextreme limit,concrete surfacemeetingcreationcrack,thiskindof crackmuch occurrenceaftertheconcrete underconstructionperiod.In theconcreteofunderconstructionbe differencein temperaturevarietymorebig,perhaps isa concreteto besubjectedtoassault ofcold waveetc.,willcause concretesurface thetemperature sharplydescend,butcreationconstringency,surface constringencyoftheconcretebesubjectedtoinnerpartconcreteofcontrol,creation verybig ofpullshoulddintbutcreationcrack,thiskindof crackusually justinmore shallowscope oftheconcretesurface creation.The alignmentofthetemperature crackusually nonesettle regulation,big areastructurethe crackoften maneuverinterleave;The sizebigger structure ofthebeamplank length,the crackrun parallelwith shortside more;Thorough withpierce throughsexoftemperature crack generaland shortside directionparallelism orcloseparallelism,crack alonglong sidecent thesegment appear,inthecenter moreairtight.Crack widththe sizebedifferent,besubjectedto temperaturevariety influencemoreobvious,winter comparebreadth,summer morenarrow.The concretetemperaturecrackthat the heatinflation causeis usuallyinthecenter thethick bothendsbe thin,but coldSuocrackof thickthin varietynot tooobvious.The emergence ofthe thiskindcrackwillcause therust eclipseof reinforcingbar,the carbonizationofconcrete,theanti-jelly whichlower concretemelt,anti-tired and anti-Shen abilityetc..Main preventionmeasure:One isas faras possiblechoosetouse lowhot ormediumhot watermire,like mineralresidue cement,powder ashfrom stovecement...etc..Two isa decreasecement dosage,cement dosageasfaraspossiblethecontrol isinthe450kg/m3following.Three is to lower waterashratio,waterashof thegeneralconcreteratiocontrol below

0.

6.Four isimprovement the bone anticipateclassto gotogether with,the Chanadd powderashfromstove orefficiently reducewater etc.to cometo reducecement dosageand lowerwater to turnhot.Five isan improvementconcreteof mixblend toprocess acraft,lower sprinkleofconcreteto buildtemperature.Six istheinaddition thatthe Chanadd ahave offixed amountto reducewaterand increaseSu,slow Ningetc.function intheconcrete,improvement theconcretemix tomatch athing ofmobility,protect water,lowerwatertoturnhot,postpone hotFeng ofemergence time.Seven isthe heatseason sprinkleto buildcan theadoptiontake toestablish tohide sunplank etc.assistance measurecontrolconcreteofWen Sheng,lower to sprinkle temperatureofbuildtheconcrete.Eight isthetemperature ofbig physical volumeconcreteshould thedint relateto structuresize,concrete structuresize morebig,temperature shoulddint morebig,so wantreasonablearrangement constructionwork preface,layering,cent thepiece sprinkletobuild,forthe convenienceofinspread hot,let upcontrol.Nine isat greatinnerpartconstitutionof thephysicalvolumeconcrete cool off piping,cold waterperhaps coldair cooloff,letup concreteof insideoutside differenceintemperature.Ten isthe supervisionwhichstrengthen concretetemperature,adopt tocooloffin time,protection measure.il istoreserve temperatureconstringency tosew.12istolet upto control,sprinkle properbeforebuildingconcreteintheJi rockand oldconcrete topbuild a5mm orso sandmata layeror usageasphalt etc.material Tu2Shua.13istostrengthen concreteto protect,theconcreteafter sprinklebuild usemoist grassLian intime,hemp slicesetc.overlay,and attentionsprinkle watertoprotect,appropriateextensionprotect time,assurancethe concretesurface beslow-moving cooloff.At thecold season,concrete surfaceshouldconstitution heatpreservation measure,in ordertopreventcold waveassault.14istheallocation bealittleamount intheconcreteof reinforcingbar perhapsadd fibermaterialconcreteoftemperaturecrackcontrolatcertainofscope inside.

5.Crack andprevention thatthe chemical reaction causeAlkalibones anticipatingthe crackthat reactioncrackandreinforcingbarrusteclipse causeisthemost familiarinthereinforcedconcretestructure ofbecause ofchemicalreaction butcauseofcrack.The concreteblend afuture reunioncreation somealkalescence ion,these ionwithsome activitytheboneanticipate creationchemicalreactionand absorbsurroundingsenvironment inofwaterbut thephysicalvolumeenlarge,make concretecrisploose,inflation opencrack.ln thiskindofcrackgeneralemergence concretestructureusage period,once appearvery difficultremediable,so shouldat underconstructionadoptvalidthe measurecarryonprevention.Main ofpreventionmeasure:While beingto choosetoanticipatewiththealkali activitysmall freestonebone.Two istheinaddition which choosetouse lowlye mirewith lowalkali orhave noalkali.Three isthe Chanwhichchoosetouseaccommodation withanticipate torepressan alkalibone toanticipate reaction.Becausetheconcretesprinkletobuild,flap Daobad perhapsisa reinforcing barprotectionlayer thinner,the harmfulmaterial getinto concretetomakereinforcing barcreationrust eclipse,the reinforcingbar physicalvolume oftherusteclipse inflation,cause concretebulge crack,the crackof thiskind typemuch isa cracklengthways,follow theposition ofreinforcingbarappear.Usually ofprevent measurefrom have:Oneis assurancereinforcingbarprotection thethickness ofthe layer.Two isa concreteclassto gotogether withtowantgood.Three isa concretetosprinkleto noteand flapDaoairtight solid.Four isareinforcingbar surfacelayer Tu2Shua antisepsiscoating.Crack processingTheemergenceofthecracknotonlywould influencestructureofwhole withjustdegree,return willcausetherusteclipseofreinforcingbar,acceleration concreteofcarbonization,lower durableandanti-ofconcretetired,anti-Shen ability.Thereforeaccording tothe propertyofcrackand concretecircumstance wewant differentiationtotreat,intimeprocessing,with assurancebuildingofsafety usage.The repairmeasure oftheconcretecrackismain tohave the following somemethod:Surface repair method,infuse syrup,the Qiansew method,the structurereinforce amethod,concrete displacementmethod,electricitychemistryprotectionmethod andimitate tolivingfromheal method.Surface repairthemethodbeakindofsimple,familiar ofrepairmethod,it mainbeapplicable tostability andto structureloading theability donthave thesurface crackofinfluence anddeep entercrackofprocessing.The processingmeasure thatis usuallyisa surface in crackdaubery cementsyrup,the wreathoxygen gum mire orat concretesurfaceTu2Shua paint,asphalt etc.antisepsis material,at protectionofinthemeantime forkeeping concretefrom continueundertheinfluence ofvarious functiontoopen crack,usually canadoption thesurfaceincrack glue to stickglass fibercloth etc.measure.1,infuse syrup,the Qiansew methodInfusea syrupmethod maintheconcretecrack beenapplicable tohave influenceorhavealreadydefend Shenrequest tothestructurewhole ofrepair,it ismake useofpressure equipmentsgum knotthe materialpress intothecrackofconcrete,gum knotthematerial hardenbehind andconcrete formationone bewhole,thus reinforceofpurpose.The incommon usegum knotmaterial hasthecementthe syrup,epoxy,A JiCXi sourester andgather ammoniaester toequalize tolearn material.The Qiansew amethod isthatthecrackbeakindof mostincommon use methodin,it usuallyis followthecrackdig slot,the Qianfill Suintheslot orrigid water materialwith attainclosing crackof purpose.The incommon useSu materialhas PVCgummire,plastics ointment,the DJi rubberetc.;ln commonuse rigidwatermaterialisthepolymercement sandsyrup.2,thestructurereinforceamethodWhen thecrackinfluencearrive concretestructureoffunction,will considerationadoptto reinforceamethodto carryon processingtotheconcretestructure.Thestructure reinforcemedium incommonusemain havethefollowinga fewmethod:Thepiece ofenlargement concretestructure inevery aspectaccumulate,outside theCapedepartment ofthe Goupiece packtype steel,adoption prepareshould thedint methodreinforce,gluetostick steelplatetoreinforce,increase toestablish fulcrumto reinforceandjet theconcrete compensation。