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I摘要随着社会的发展，生产力和生产技术的不断提高，建筑业的迅猛发展，大体积混凝土在大型钢筋混凝土结构中广泛应用。大体积混凝土具有结构厚实，混凝土量大，工程条件复杂，施工技术要求高的特点。大体积混凝土浇筑后水泥水化热温升较高，由于体积较大，聚集在混凝土内部的水泥水化热不易散发，混凝土内部温度显著升高，造成混凝土内外温差较大，混凝土表面易产生裂缝。混凝土的拌合水中，只有少部分水是水泥水化所必需的，其余绝大部分的水分会蒸发掉。混凝土中多余水分的蒸发是引起大体积混凝土体积收缩的主要原因之一。当收缩变形下产生的收缩应力大于混凝土抗拉强度时，混凝土就会出现裂缝。大体积混凝土的裂缝，会直接影响建筑物的安全性、经济性和耐久性。本文以大体积混凝土施工阶段的裂缝控制为研究对象，采用理论与实际相结合，定性分析与定量分析相结合的方法，以定性分析为主，定量分析为辅，研究分析大体积混凝土施工裂缝的成因，并在成因分析的基础上，提出经济、合理、有效的大体积混凝土施工裂缝的控制技术和措施。在大体积混凝土施工以及施工中所存在的问题的基础上，本文系统地介绍大体积混凝土的施工裂缝的种类，描述各裂缝的现象与特点，并分别进行成因分析。在成因分析的基础上，综合地从材料选择及配合比设计，施工现场管理，施工技术管理，以及温度控制等四个方面来介绍大体积混凝土施工裂缝的控制。关键词：大体积混凝土裂缝温度控制IIABSTRACTWiththesocialdevelopment,continuousimprovementoftheproductivityandproductiontechnology,themassconcretehasbeenwidelyusedinlargereinforcedconcretestructure.Massiveconcretehasthecharacteristicsofthickandlargevolume,complexprojectconditionsandhighconstructiontechnologydemanding.Duetothelargevolume,massconcretepouringcementhydrationtemperaturerisesafterthehigheraggregateintheconcreteheatofhydrationofcementwithineasydistribution,significantlyincreasedinternaltemperatureofconcrete,resultinginalargertemperaturedifferencebetweeninsideandoutsideconcrete,andthen,thesurfaceoftheconcreteiseasytocracking.Onlyasmallpartoftheconcretemixingwaterisnecessaryforhydrationofcement,theotherpartwillevaporate.Evaporationofexcesswaterinconcreteisoneofthemainfactorsthatcausingvolumeshrinkageofmassconcrete.Whentheshrinkagestressthatproducedbytheshrinkagestrainisgreaterthanthetensilestrengthoftheconcrete,crackswilloccur.Thus,cracksinmassconcretestructureswilldirectlyaffectthesafety,economyanddurability.Thispaperphasesofthemassconcretecrackcontrolforthestudy,usesthecombinationsoftheoryandpractice,qualitativeanalysisandquantitativeanalysis,andqualitativeanalysissupplementedbyquantitativeanalysis,researchesthefactorsthatleadtocracksofthemassconcreteconstruction,andthen,putsforwardtheeconomic,rationalandeffectiveconstructionofmassconcretecrackcontroltechnologiesandmeasures.Accordingtothemassconcreteconstructionandtheproblemsofmassconcreteconstruction,thispapersystematicallydescribestheconstructionofmassconcretetypesofcracksandthecrackphenomenon,andanalysisthecausesofthecracks.Basedonanalysisofthecauses,thepaperpresentsmassconcretecrackcontrolsintegratedl1yfrommaterialsselectionandmixdesign,constructionsitemanagement,constructiontechnologymanagement,aswellastemperaturecontrol.Keywords：MassConcrete；Crack；CrackControl；TemperatureControlIII目录摘要................................................................................................................................IABSTRACT.................................................................................................................II1绪论............................................................................................................................11.1研究背景.............................................................................................................11.2国内外研究现状.................................................................................................21.3本文的研究内容.................................................................................................42大体积混凝土施工....................................................................................................52.1大体积混凝土施工方法.....................................................................................52.2大体积混凝土施工中的问题.............................................................................73大体积混凝土施工裂缝............................................................................................83.1施工裂缝种类与成因.........................................................................................83.2施工裂缝成因总结...........................................................................................104大体积混凝土施工裂缝控制..................................................................................134.1材料选择及配合比设计...................................................................................134.2施工现场管理...................................................................................................224.3施工技术管理...................................................................................................244.4温度控制...........................................................................................................305总结..........................................................................................................................415.1研究总结...........................................................................................................415.2建议与展望.......................................................................................................42致谢..............................................................................................................................43参考文献......................................................................................................................44华中科技大学毕业设计论文11绪论1.1研究背景1.1.1大体积混凝土的定义不同国家对大体积混凝土的定义不同。美国混凝土学会有过规定：任何现浇混凝土，其尺寸达到必须解决水化热及随之引起的体积变形问题，