超高韌性纖維混凝土材料（UHTCC）是一種具有顯著應(yīng)變硬化和多縫開(kāi)裂特征的水泥基材料,其拉伸應(yīng)變通常能到達(dá)數(shù)個(gè)百分點(diǎn),該類材料基于微觀力學(xué)原理設(shè)計(jì)制備。作為一種具有高韌性和高耐久性的新型水泥基材料,UHTCC在需要承受反復(fù)循環(huán)荷載的結(jié)構(gòu)中具有廣闊的應(yīng)用前景�，F(xiàn)代基礎(chǔ)設(shè)施的建設(shè)和發(fā)展對(duì)混凝土結(jié)構(gòu)在長(zhǎng)期荷載和交變環(huán)境作用下的服役壽命提出了更高要求。因此,對(duì)于UHTCC在循環(huán)荷載作用下的抗疲勞性能研究具有重要性和迫切性。本文開(kāi)展了 UHTCC及其功能梯度結(jié)構(gòu)的疲勞性能研究,具體內(nèi)容如下:1.研究了不同應(yīng)力水平條件下UHTCC的壓縮疲勞性能;建立了考慮應(yīng)力水平效應(yīng)的材料疲勞失效變形概率模型;在疲勞損傷失效過(guò)程中,發(fā)現(xiàn)微裂紋在疲勞源區(qū)萌生,在疲勞過(guò)渡區(qū)擴(kuò)展,最終在裂縫擴(kuò)展區(qū)形成主裂紋,并發(fā)現(xiàn)了三種疲勞導(dǎo)致的纖維失效模式。2.研究了荷載頻率對(duì)UHTCC壓縮疲勞性能的影響;發(fā)現(xiàn)UHTCC的疲勞壽命和變形受到荷載頻率的影響;揭示了第二階段應(yīng)變率、基于循環(huán)數(shù)的第二階段應(yīng)變率和疲勞壽命之間的量化關(guān)系,提出了可用于疲勞壽命預(yù)測(cè)的系列公式;建立了考慮頻率效應(yīng)的疲勞失效應(yīng)變概率模型。3.提出了基于Weibull... 

【文章來(lái)源】：浙江大學(xué)浙江省 211工程院校 985工程院校 教育部直屬院校

【文章頁(yè)數(shù)】：240 頁(yè)

【學(xué)位級(jí)別】：博士

【文章目錄】：
ACKNOWLEDGEMENTS
致謝
ABSTRACT
摘要
CHAPTER 1 INTRODUCTION
    1.1 Background
    1.2 Ultra-High Toughness Cementitious Composite （UHTCC）
        1.2.1 Mechanical Properties of UHTCC
        1.2.2 Durability of UHTCC
        1.2.3 Practical Application Cases of UHTCC
    1.3 Review on Fatigue Behavior of Fiber-Reinforced Concrete and UHTCC
        1.3.1 Fatigue Behavior of Fiber-Reinforced Concrete
        1.3.2 Fatigue Behavior of UHTCC
    1.4 Research Objectives and Thesis Outline
        1.4.1 Research Motivation and Objectives
        1.4.2 Thesis Outline
    References
CHAPTER 2 COMPRESSIVE FATIGUE BEHAVIOR OF UHTCC
    2.1 Introduction
    2.2 Experimental Program
        2.2.1 Specimen Preparation
        2.2.2 Testing Methods
    2.3 Fatigue Life and Distribution
    2.4 Cyclic Creep Curve
    2.5 Secondary Strain Rate
    2.6 Comparison of Monotonic and Fatigue Deformation
    2.7 Probabilistic Model of Fatigue Failure Strain
    2.8 Fatigue Damage Mechanism
        2.8.1 Fatigue Failure Mode of Specimen
        2.8.2 Static and Fatigue Failure Surface
        2.8.3 SEM Analysis
        2.8.4 Discussion of the Static and Fatigue Damage Process
    2.9 Fatigue-induced Fiber Failure Mechanism
        2.9.1 Results of XCT Test
        2.9.2 SEM Test and Fiber Failure Mechanism
    2.10 Conclusions
    References
CHAPTER 3 FREQUENCY EFFECT ON THE FATIGUE BEHAVIOR OF UHTCC
    3.1 Introduction
    3.2 Material and Testing Method
    3.3 Fatigue Life
    3.4 Fiber Failure Modes
    3.5 Fatigue Deformation
    3.6 Secondary Strain Rate
    3.7 Probabilistic Model of Failure Strain
    3.8 Conclusions
    References
CHAPTER 4 FATIGUE DEFORMATION MODEL OF PLAIN AND FIBER-REINFORCED CONCRETE
    4.1 Introduction
    4.2 Fatigue Deformation Model Based on Weibull Function
        4.2.1 Three-Stage Fatigue Deformation and Cumulative Distribution Function
        4.2.2 Weibull Function
        4.2.3 Fatigue Deformation Model
        4.2.4 Model Sensitivity to Its Parameters
        4.2.5 Model Application
    4.3 Model Validation
    4.4 Analysis of Model Parameters
        4.4.1 Model Parameters of UHTCC
        4.4.2 Model Parameters of Plain Concrete
        4.4.3 Discussion
    4.5 Deformation-based Method for Fatigue Life Prediction
    4.6 Conclusion
    References
CHAPTER 5 TENSILE FATIGUE BEHAVIOR OF UHTCC
    5.1 Introduction
    5.2 Experimental Program
    5.3 Crack Pattern
    5.4 Fatigue Deformation
    5.5 Failure Surface
    5.6 Microscopic Investigation
    5.7 Fatigue Life and P-S-N Models
        5.7.1 Distribution of Tensile Strength and Fatigue Life
        5.7.2 P-S-N Models
        5.7.3 Comparison of Fatigue Lives
    5.8 Conclusion
    References
CHAPTER 6 STATIC AND FATIGUE BEHAVIORS OF UHTCC FUNCTIONALLY-GRADED STRUCTURES
    6.1 Introduction
    6.2 Assembled Participating Permanent Formwork Using UHTCC
        6.2.1 Design of UHTCC Permanent Formwork
        6.2.2 Fabrication of Reinforced Concrete Member Using UHTCC Permanent Formwork for Bending Test
        6.2.3 Test Results and Optimization of the Assembled Permanent Formwork
    6.3 Reinforced Participating Permanent Formwork Using UHTCC
        6.3.1 Design of Reinforced UHTCC Permanent Formwork
        6.3.2 Preparation of Beam Specimens Using Reinforced UHTCC Permanent Formwork
        6.3.3 Testing Methods and Results
        6.3.4 Strain Profiles and Stiffness of Beam Specimens
        6.3.5 Analysis of Failure Process of Beam Specimens Based on Digital Image Correlation（DIC）
        6.3.6 Theoretical Analysis and Optimization of the Formwork Design
        6.3.7 Manufacturing Tolerance
    6.4 Fatigue Behavior of UHTCC Functionally-graded Beam
        6.4.1 Experimental Program
        6.4.2 Results of Static Tests
        6.4.3 Fatigue Life of Reinforced Concrete Beams with UHTCC Layer
        6.4.4 Mid-span Deflection and Cracking Modes under Fatigue Loading
        6.4.5 Strain Profiles of Beam Specimens
        6.4.6 Strain Range of Longitudinal Bar and UHTCC
        6.4.7 Fatigue Degradation of UHTCC Layer
        6.4.8 Fatigue Strength of Longitudinal Bar
        6.4.9 Fatigue Enhancement Mechanism of UHTCC Layer
    6.5 Conclusions
    References
CHAPTER 7 CONCLUSIONS AND RECOMMENDATIONS
    7.1 Concluding Remarks
    7.2 Scientific Contributions and Research Impacts
    7.3 Recommendations for Future Work
CURRICULUM VITAE AND PUBLICATIONS



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