Contents

Preface i About the Author v

1 Introduction 1

1.1 The Significance of Thermal Stress in Mass Concrete 1

1.2 The Features of Thermal Stresses in Concrete Structures 3

1.3 The Variation of Temperature and Thermal Stress of Mass Concrete with Time 4

1.3.1 The Variation of Temperature of Mass Concrete with Time 4

1.3.2 The Variation of the Thermal Stress in Mass Concrete 5

1.4 Kinds of Thermal Stress 6

1.5 Analysis of Thermal Stress of a Massive Concrete Structure 6

1.6 Thermal Stress—The Cause of Crack 7

1.7 Technical Measures for Control of Thermal Stress and Prevention of Cracking 8

1.8 The Experience of the Temperature Control and Crack Prevention

2 ConductionofHeatinMassConcrete,BoundaryConditions,andMethodsofSolution11

2.1 DifferentialEquationofHeatConduction,InitialandBoundaryConditions11

2.1.1 DifferentialEquationofHeatConduction11

2.1.2 InitialCondition12

2.1.3 BoundaryConditions13

2.1.4 TheApproximateTreatmentoftheThirdKindofBoundaryCondition14

2.2 SurfaceConductanceandComputationofSuperficialThermalInsulation16

2.2.1 SurfaceConductanceβ16

2.2.2 ComputationoftheEffectofSuperficialThermalInsulation17

2.3 AirTemperature19

2.3.1 AnnualVariationofAirTemperature19

2.3.2 ColdWave19

2.4 TemperatureIncrementsduetoSunshine20

2.4.1 SunRadiationonHorizontalSurface20

2.4.2 TemperatureIncrementoftheDamSurfaceduetoSunshine22

2.4.3 InfluenceofSunshineontheTemperatureofHorizontalLiftSurface22

2.5 EstimationofWaterTemperatureinReservoir25

2.6 NumericalComputationofWaterTemperatureinReservoir28

2.7 ThermalPropertiesofConcrete29

2.8 HeatofHydrationofCementandtheAdiabaticTemperatureRiseofConcrete31

2.8.1 HeatofHydrationofCement31

2.8.2 AdiabaticTemperatureRiseofConcrete32

2.9 TemperatureontheSurfaceofDam35

2.10 TheAutogenousDeformationofConcrete36

2.11 Semi-MatureAgeofConcrete36

2.11.1 MethodforDeterminingtheSemi-MatureAgeofConcrete37

2.11.2 FormulasforComputingtheSemi-MatureAgeofConcrete38

2.11.3 MeaningofSemi-MatureAgeinEngineering40

2.11.4 ExampleoftheInfluenceofSemi-MatureAge40

2.11.5 MeasuresforAdjustingtheSemi-MatureAgesofConcrete41

2.11.6 Conclusions42

2.12 DeformationofConcreteCausedbyChangeofHumidity42

2.13 CoefficientsofThermalExpansionofConcrete43

2.14 SolutionofTemperatureFieldbyFiniteDifferenceMethod44

3 TemperatureFieldintheOperationPeriodofaMassiveConcreteStructure49

3.1 DepthofInfluenceoftheVariationofExteriorTemperatureintheOperationPeriod49

3.1.1 DepthofInfluenceofVariationofWaterTemperature49

3.1.2 DepthofInfluenceofVariationofAirTemperature50

3.2 VariationofConcreteTemperaturefromtheBeginningofConstructiontothePeriodofOperation53

3.3 SteadyTemperatureFieldofConcreteDams54

4 PlacingTemperatureandTemperatureRiseofConcreteLiftduetoHydrationHeatofCement57

4.1 MixingTemperatureofConcrete—T057

4.2 TheFormingTemperatureofConcreteT158

4.3 PlacingTemperatureofConcreteTp60

4.4 TheoreticalSolutionofTemperatureRiseofConcreteLiftduetoHydrationHeatofCement62

4.4.1TemperatureRiseduetoHydrationHeatinConcrete

LiftwithFirstKindofBoundaryCondition4.4.2TemperatureRiseduetoHydrationHeatinConcrete

LiftwithThirdKindofBoundaryCondition 64

4.4.3 TemperatureRiseduetoHydrationHeatwithAdiabaticTemperatureRiseExpressedbyCompoundExponentials66

4.5 TheoreticalSolutionofTemperatureFieldofConcreteLiftduetoSimultaneousActionofNaturalCoolingandPipeCooling67

4.6 TemperatureFieldinConcreteLiftComputedbyFiniteDifferenceMethod69

4.6.1 TemperatureFieldinConcreteLiftduetoHydrationHeatComputedbyFiniteDifferenceMethod69

4.6.2 TemperatureFieldduetoHydrationHeatinConcreteLiftwithCoolingPipeComputedbyFiniteDifferenceMethod70

4.7 PracticalMethodforComputingTemperatureFieldinConstructionPeriodofConcreteDams72

4.7.1 PracticalMethodforComputingTemperatureFieldinConcreteLiftwithoutPipeCooling74

4.7.2 InfluenceofthePlacingTemperatureTpoftheNewConcrete75

4.7.3 PracticalMethodforComputingTemperatureinConcreteLiftwithoutPipeCooling77

4.7.4 PracticalMethodforComputingTemperatureFieldinConcreteLiftwithPipeCooling77

4.7.5 PracticalTreatmentofBoundaryConditionontheTopSurface80

5 NaturalCoolingofMassConcrete83

5.1 CoolingofSemi-InfiniteSolid,ThirdKindofBoundaryCondition83

5.2 CoolingofaSlabwithFirstKindofBoundaryCondition85

5.3 CoolingofaSlabwithThirdKindofBoundaryCondition89

5.4 TemperatureinaConcreteSlabwithHarmonicSurfaceTemperature91

5.4.1 ConcreteSlabwithZeroInitialTemperatureandHarmonicSurfaceTemperature91

5.4.2 ConcreteSlab,InitialTemperatureT0,HarmonicSurfaceTemperature94

5.5 TemperatureinaSlabwithArbitraryExternalTemperature98

5.6 CoolingofMassConcreteinTwoandThreeDirections,TheoremofProduct101

6 Stress-StrainRelationandAnalysisofViscoelasticStressofMassConcrete105

6.1 Stress-StrainRelationofConcrete105

6.1.1 StrainofConcreteduetoConstantStress105

6.1.2 StrainofConcreteduetoVariableStress107

6.1.3 ModulusofElasticityandCreepofConcrete107

6.1.4 LateralStrainandPoisson’sRatioofConcrete110

6.2 StressRelaxationofConcrete111

6.2.1 StressRelaxationofConcreteSubjectedtoConstantStrain111

6.2.2 MethodforComputingtheRelaxationCoefficientfromCreepofConcrete112

6.2.3 FormulasforRelaxationCoefficient114

6.3 ModulusofElasticity,UnitCreep,andRelaxationCoefficientofConcreteforPreliminaryAnalysis115

6.4 TwoTheoremsAbouttheInfluenceofCreepontheStressesandDeformationsofConcreteStructures115

6.5 ClassificationofMassiveConcreteStructuresandMethodofAnalysis117

6.6 MethodofEquivalentModulusforAnalyzingStressesinMaturedConcreteduetoHarmonicVariationofTemperature117

7 ThermalStressesinFixedSlaborFreeSlab121

7.1 ThermalStressesinFixedSlab121

7.1.1 ComputationoftheTemperatureField121

7.1.2 TheElasticThermalStress121

7.1.3 TheViscoelasticThermalStresses123

7.1.4 TheThermalStressesinFixedSlabDuetoHydrationHeatofCement123

7.2 MethodforComputingThermalStressesinaFreeSlab126

7.2.1 ElasticThermalStressinaFreeSlabWhentheModulusofElasticityisConstant126

7.2.2 ViscoelasticThermalStressinaFreeSlabConsideringtheInfluenceofAge128 2100433B

《大体积混凝土温度应力与温度控制(第2版)》全面阐述了大体积混凝土温度应力和温度控制的基本理论、工程理念和技术措施，全书分为三部分：第一部分是混凝土结构温度场和温度徐变应力的计算方法；第二部分是各种大体积混凝土结构，包括浇筑块、重力坝、支墩坝、拱坝、嵌固板、自由墙、基础梁、混凝土杆件、隧洞和孔口的温度场和温度徐变应力的变化规律和计算方法；第三部分是控制温度、防止裂缝的工程理念、技术措施和实践经验，包括各种温差的控制、混凝土原材料的优选、混凝土预冷、水管冷却、表面保温的计算方法和技术措施，国内外实际工程控制温度防止裂缝的实践经验。

大体积砼养护时的温度控制一般有两种方法：

一种是降温法，即在砼浇筑成型后，通过循环冷却水降温，从结构物的内部进行温度控制；

另一种是保温法，即砼浇筑成型后，通过保温材料、碘钨灯或定时喷浇热水、蓄存热水等办法，提高砼表面及四周散热面的温度，从结构物的外部进行温度控制。保温法基本原理是利用砼的初始温度加上水泥水化热的温升，在缓慢的散热过程中（通过人为控制），使砼获得必要的强度。

第1篇 基本理论与计算方法

第1章 绪论

第2章 涵闸混凝土的热学性能和力学性能

第3章 涵闸混凝土的温度计算

第4章 涵闸混凝土的温度应力分枥

第5章 计算温度和温度应力的有限单元法

第6章 水管冷却的降温计算

第7章 混凝土的湿度变化和干缩应力

第8章 温度控制和预防裂缝的措施

第2篇 工程经验

第9章 淮安枢纽立交地涵的温度控制

第10章 二河闸的温度控制

第11章 刘家道口节制闸的温度控制

第12章 姜唐湖退水闸的温度控制

第13章 燕山水库溢洪闸的温度控制

第14章 涵闸混凝土温度控制和预防裂缝的工程经验2100433B

涵闸是常见的水工建筑物，是各类防洪、水力发电和引供水工程的重要组成部分。《涵闸混凝土的温度应力与温度控制》共分两篇，第一篇是基本理论与计算方法，第二篇是工程经验，在第二篇中介绍了淮河人海水道淮安立交地涵二河闸、姜唐湖退水闸、刘家道口节制闸和燕山水库泄洪闸的工程经验。《涵闸混凝土的温度应力与温度控制》由王同生、于子忠、张勇、李永江、罗隆芒和石红伟共同编写，王同生负责统稿。