现代混凝土早龄期裂缝控制（英文版）

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1 Introduction 11.1 Early-age Cracking of Modern Concrete . 11.1.1 Significance of Early-age Cracking 11.2 Causes of Early-age Cracking 21.3 Measures for Controlling Early-age Cracking of Concrete 31.3.1 Mitigating the Drop in Internal Relative Humidity . 31.3.2 Controlling the Change of Temperature 41.3.3 Decreasing the Early-age Shrinkage . 41.3.4 Increasing the Tensile Strength . 51.4 Objectives and Scope . 6References 92 Techniques and Methods for Evaluating the Early-ageCracking Resistance of Modern Concrete 132.1 Introduction . 132.2 Early-age Internal Relative Humidity in Concrete . 132.2.1 Test Device andMethod . 132.2.2 Calculation of Internal Relative HumidityDecrease Rate 152.3 Early-age Autogenous Shrinkage . 152.3.1 Test Device andMethod . 152.3.2 Calculation of Autogenous Shrinkage 162.4 Early-age Mechanical Properties . 182.4.1 Compressive Strength . 182.4.2 Tensile Strength 192.4.3 Static Elastic Modulus . 192.4.4 Dynamic Elastic Modulus 202.4.5 Bond Behavior . 222.5 Early-age Tensile Creep . 232.5.1 Test Device andMethod . 232.5.2 Calculation of Tensile Creep . 26viiviii Contents2.5.3 Calculation of Tensile Creep Coefficient . 272.5.4 Calculation of Specific Tensile Creep 272.6 Early-age Cracking Resistance Under CircumferentialRestrained Condition . 272.6.1 Test Device andMethod . 272.6.2 Calculation of Residual Stress 302.6.3 Calculation of Stress Rate 302.6.4 Calculation of Cracking Potential . 312.6.5 Calculation of Stress Relaxation 312.7 Early-age Cracking Resistance Under Uniaxial RestrainedCondition . 342.7.1 Test Device andMethod . 342.7.2 Calculation of Temperature History . 352.7.3 Calculation of Creep 362.7.4 Calculation of Cracking Resistance 36References 373 Evaluation on Early-age Cracking Resistance of Concrete . 413.1 Introduction . 413.2 Internal Relative Humidity in Early-age Concrete . 423.2.1 Internal Relative Humidity . 423.2.2 Critical Time of Internal Relative Humidity . 443.2.3 Internal Relative Humidity Decrease Rate 453.2.4 Moisture Diffusion 473.2.5 Prediction Models for Internal Relative Humidity 483.3 Early-age Cracking Resistance of Concrete with DifferentWater-to-Cement Ratios Under Circumferential RestrainedCondition . 573.3.1 Mechanical Properties . 573.3.2 Free Shrinkage . 583.3.3 Steel Ring Strain . 593.3.4 Residual Stress . 603.3.5 Stress Relaxation . 613.3.6 Cracking Resistance . 643.4 Early-age Cracking Resistance of Concrete with DifferentWater-to-Cement Ratios Under Uniaxial RestrainedCondition . 653.4.1 Temperature History 653.4.2 Autogenous Shrinkage . 673.4.3 Restrained Stress . 683.4.4 Tensile Creep 713.4.5 Cracking Resistance . 733.5 Early-age Cracking Resistance of High PerformanceConcrete with Different Curing Temperatures UnderUniaxial Restrained Condition . 74Contents ix3.5.1 Autogenous Shrinkage . 743.5.2 Ratio of Stress to Tensile Strength . 823.5.3 Cracking Resistance . 843.6 Summary . 85References 864 Early-age Cracking Control on Concrete with Fly Ash 914.1 Introduction . 914.2 Mechanical Properties 924.2.1 Compressive Strength . 934.2.2 Tensile Strength 964.2.3 Tensile Young’s Modulus 1004.3 Early-age Cracking Resistance of High PerformanceConcrete with Fly Ash Under Circumferential RestrainedCondition . 1054.3.1 Free Shrinkage . 1054.3.2 Steel Ring Strain . 1064.3.3 Residual Stress . 1074.3.4 Stress Rate . 1094.3.5 Stress Relaxation . 1104.4 Early-age Cracking Resistance of High PerformanceConcrete with Fly Ash Under Uniaxial RestrainedCondition . 1114.4.1 Autogenous Shrinkage . 1124.4.2 Temperature History 1134.4.3 Restrained Stress . 1144.4.4 Tensile Creep 1184.4.5 Cracking Resistance . 1194.5 Summary . 120References 1215 Early-age Cracking Control on Concrete with GroundGranulated Blast Furnace Slag . 1255.1 Introduction . 1255.2 Mechanical Properties 1265.3 Early-age Cracking Resistance of High PerformanceConcrete with Ground Granulated Blast Furnace SlagUnder Circumferential Restrained Condition . 1285.3.1 Free Shrinkage . 1285.3.2 Steel Ring Strain . 1285.3.3 Residual Stress . 1295.3.4 Stress Rate . 1305.3.5 Cracking Potential 1315.3.6 Stress Relaxation . 132x Contents5.4 Early-age Cracking Resistance of High PerformanceConcrete with Ground Granulated Blast Furnace SlagUnder Uniaxial Restrained Condition . 1335.4.1 Temperature History 1335.4.2 Autogenous Shrinkage . 1345.4.3 Restrained Stress . 1355.4.4 Cracking Resistance . 1385.5 Summary . 139References 1406 Early-age Cracking Control on Concrete with Silica Fume 1436.1 Introduction . 1436.2 Mechanical Properties 1446.3 Early-age Cracking Resistance of High Strength Concretewith Silica Fume Under Uniaxial Restrained Condition 1466.3.1 Temperature History 1466.3.2 Autogenous Shrinkage . 1486.3.3 Tensile Creep 1506.3.4 Restrained Stress . 1526.3.5 Cracking Resistance . 1546.4 Summary . 155References 1557 Early-age Cracking Control on Concrete with 3D Hooked-EndSteel Fiber 1597.1 Introduction . 1597.2 Mechanical Properties 1607.3 Tensile Creep of 3D Hooked-End Steel Fiber ReinforcedConcrete Under a Constant Tensile Load . 1647.3.1 Tensile Creep of Concrete with Different Contentsof 3D Hooked-End Steel Fiber 1647.3.2 Tensile Creep of Concrete with Different ThermalTreatment Temperatures . 1687.3.3 Prediction Model for Early-age Tensile Creep . 1707.4 Early-age Cracking Resistance of High Strength ConcreteReinforced with 3D Hooked-End Steel Fiber UnderUniaxial Restrained Condition . 1757.4.1 Temperature History 1757.4.2 Autogenous Shrinkage . 1777.4.3 Restrained Stress . 1807.4.4 Cracking Resistance . 1827.5 Early-age Cracking Resistance of 3D Hooked-End SteelFiber Reinforced Concrete Under Different CuringTemperatures 1847.5.1 Temperature History 1847.5.2 Autogenous Shrinkage . 186Contents xi7.5.3 Restrained Stress . 1897.5.4 Tensile Creep 1917.5.5 Cracking Resistance . 1947.6 Summary . 195References 1968 Early-age Cracking Control on Concrete with 5D Hooked-EndSteel Fiber 1998.1 Introduction . 1998.2 Mechanical Properties 2008.3 Early-age Cracking Resistance of Concrete with 5DHooked-End Steel Fiber Under Circumferential RestrainedCondition . 2018.3.1 Steel Ring Strain . 2018.3.2 Residual Stress . 2038.3.3 Free Shrinkage . 2038.3.4 Stress Rate . 2048.3.5 Cracking Potential 2048.3.6 Stress Relaxation . 2058.4 Early-age Cracking Resistance of Concrete with 5DHooked-End Steel Fiber Under Uniaxial RestrainedCondition . 2088.4.1 Temperature History 2088.4.2 Autogenous Shrinkage . 2098.4.3 Restrained Stress . 2128.4.4 Cracking Resistance . 2148.5 Summary . 216References 2169 Early-age Cracking Control on Concrete with PolypropyleneFiber . 2199.1 Introduction . 2199.2 Mechanical Properties 2209.3 Early-age Autogenous Shrinkage of High StrengthConcrete with Polypropylene Fiber . 2229.3.1 Temperature History 2229.3.2 Autogenous Shrinkage . 2229.3.3 Ultrasonic Velocity 2259.3.4 Prediction Model of Autogenous Shrinkage StrainBased on Ultrasonic Velocity . 2289.4 Early-age Tensile Creep of Concrete with PolypropyleneFiber . 2319.4.1 Autogenous Shrinkage . 2319.4.2 Tensile Creep 2329.4.3 Mechanism of Polypropylene Fiber Reinforcement 2349.4.4 Modeling of Creep of Fiber Reinforced Concrete 236xii Contents9.5 Early-age Cracking Resistance of High Strength Concretewith Polypropylene Fiber Under CircumferentialRestrained Condition . 2389.5.1 Free Shrinkage . 2389.5.2 Steel Ring Strain . 2399.5.3 Residual Stress . 2399.5.4 Stress Rate . 2409.5.5 Cracking Potential 2419.5.6 Stress Relaxation . 2429.6 Early-age Cracking Resistance of High PerformanceConcrete with Different Amounts of Polypropylene FiberUnder Uniaxial Restrained Condition . 2439.6.1 Temperature History 2439.6.2 Autogenous Shrinkage . 2449.6.3 Restrained Stress . 2459.6.4 Compressive and Tensile Creep . 2479.6.5 Cracking Resistance . 2499.7 Early-age Cracking Resistance of High PerformanceConcrete with Different Polypropylene Fiber LengthsUnder Uniaxial Restrained Condition . 2509.7.1 Temperature History 2509.7.2 Autogenous Shrinkage . 2519.7.3 Restrained Stress . 2529.7.4 Tensile Creep 2549.7.5 Cracking Resistance . 2569.8 Summary . 257References 25810 Early-age Cracking Control on High Strength Concretewith Polyvinyl Alcohol Fibers 26310.1 Introduction . 26310.2 Mechanical Properties 26410.3 Early-age Cracking Resistance of High Strength Concretewith Polyvinyl Alcohol Fibers Under CircumferentialRestrained Condition . 26710.3.1 Residual Stress . 26810.3.2 Stress Rate . 26810.3.3 Stress Relaxation . 26910.3.4 Cracking Potential 27010.4 Early-age Cracking Resistance of High Strength Concretewith Polyvinyl Alcohol Fiber Under Uniaxial RestrainedCondition . 27310.4.1 Temperature History 27310.4.2 Autogenous Shrinkage . 27310.4.3 Restrained Stress . 276Contents xiii10.4.4 Compressive and Tensile Creep . 27910.4.5 Cracking Resistance . 28210.5 Summary . 283References 28311 Early-age Cracking Control on High Strength Concretewith Nano-CaCO3 . 28711.1 Introduction . 28711.2 Mechanical Properties 28811.3 Early-age Cracking Resistance of High Strength Concretewith Nano-CaCO3 Under Circumferential RestrainedCondition . 29011.3.1 Free Shrinkage . 29011.3.2 Residual Stress . 29111.3.3 Cracking Potential 29211.3.4 Stress Relaxation . 29311.3.5 Tensile Creep 29511.3.6 Relationship Between Relaxation and Creep 29511.4 Early-age Cracking Resistance of High Strength Concretewith Nano-CaCO3 Under Uniaxial Restrained Condition . 29811.4.1 Temperature History 29811.4.2 Restrained Stress . 29911.4.3 Autogenous Shrinkage . 30011.4.4 Tensile Creep 30111.4.5 Cracking Resistance . 30411.4.6 Simplified Stress–Strain Failure Criterion 30511.5 Summary . 308References 30812 Early-age Cracking Control on High Strength Concretewith Crystalline Admixture 31112.1 Introduction . 31112.2 Mechanical Properties 31212.3 Early-age Cracking Resistance of High Strength Concretewith Crystalline Admixture Under CircumferentialRestrained Condition . 31512.3.1 Free Shrinkage . 31512.3.2 Residual Stress . 31612.3.3 Stress Rate . 31712.3.4 Cracking Potential 31912.3.5 Stress Relaxation . 32012.4 Summary . 321References 32213 Early-age Cracking Control on Concrete with MgOCompound Expansive Agent . 32513.1 Introduction . 32513.2 Deformation of Concrete 32613.2.1 Free Strain . 32613.2.2 Autogenous Strain 32813.3 Restrained Stress of Concrete 33113.3.1 Restrained Stress . 33113.3.2 Stress Relaxation and Ratio of Stress to TensileStrength . 33313.4 Early-age Creep Behavior . 33513.4.1 Compressive Creep . 33513.4.2 Tensile Creep 33713.5 Cracking Resistance 33813.5.1 Parameters for Evaluating Cracking Resistance 33813.5.2 Evaluation of Cracking Resistance 34113.6 Simplified Stress–Strain Cracking Criterion 34213.7 Summary . 344References 34414 Early-age Cracking Control on Concrete with TemperatureRise Inhibitor . 34914.1 Introduction . 34914.2 Mechanical Properties 35014.3 Early-age Cracking Resistance of High Strength Concretewith Temperature Rise Inhibitor Under Uniaxial RestrainedCondition . 35114.3.1 Temperature History 35114.3.2 Restrained Stress . 35214.3.3 Autogenous Shrinkage . 35314.3.4 Tensile Creep 35614.3.5 Cracking Resistance . 36014.3.6 Simplified Stress–Strain Failure Criterion 36114.4 Summary . 364References 36415 Early-age Cracking Control on High Strength Concretewith Shrinkage Reducing Admixture 36715.1 Introduction . 36715.2 Mechanical Properties 36815.3 Early-age Cracking Resistance of High StrengthConcrete with Shrinkage Reducing Admixture UnderCircumferential Restrained Condition . 37015.3.1 Free Shrinkage . 37015.3.2 Steel Ring Strain . 37115.3.3 Residual Stress . 37215.3.4 Stress Rate . 37215.3.5 Cracking Potential 37315.3.6 Stress Relaxation . 37515.4 Early-age Cracking Resistance of High Strength Concretewith Shrinkage Reducing Admixture Under UniaxialRestrained Condition . 37715.4.1 Temperature History 37715.4.2 Autogenous Shrinkage . 37815.4.3 Tensile Creep 38015.4.4 Restrained Stress . 38215.4.5 Cracking Resistance . 38315.5 Summary . 384References 38416 Early-age Cracking Control on Concrete with ReinforcingBars . 38716.1 Introduction . 38716.2 Early-age Bond Behavior Between High Strength Concreteand Reinforcing Bars . 38816.2.1 Relationship Between Bond Strength and Age 38816.2.2 Relationship Between Bond Strength and ConcreteStrength . 39216.2.3 Prediction Model for the Slip Correspondingto Bond Strength . 39616.2.4 Prediction Model for Bond Stress–SlipRelationship Between Reinforcing Bars and HighStrength Concrete . 39716.3 Early-age Cracking Resistance of Reinforced HighStrength Concrete Under Uniaxial Restrained Condition . 40116.3.1 Temperature History 40116.3.2 Autogenous Shrinkage . 40316.3.3 Restrained Stress . 40616.3.4 Tensile Creep 40816.3.5 Cracking Resistance . 40816.4 Summary . 409References 41017 Early-age Cracking Control on Concrete with Internal Curing 41317.1 Introduction . 41317.2 Early-age Cracking Control on Concrete with InternalCuring by Super Absorbent Polymers . 41417.2.1 Mechanical Properties . 41417.2.2 Temperature History 41617.2.3 Autogenous Shrinkage . 41817.2.4 Restrained Stress . 419xvi Contents17.2.5 Tensile Creep 42117.2.6 Cracking Resistance . 42317.3 Early-age Cracking Control on Concrete with InternalCuring by Pre-wetted Lightweight Aggregates 42417.3.1 Mechanical Properties . 42417.3.2 Steel Ring Strain . 42817.3.3 Residual Stress . 42917.3.4 Stress Rate . 43017.3.5 Stress Relaxation . 43117.3.6 Tensile Creep 43217.3.7 Relationship Between Relaxation and Creep 43417.4 Summary . 435References 436