1st Edition

Concrete Fracture A Multiscale Approach

By Jan G.M. van Mier Copyright 2013
    382 Pages 194 B/W Illustrations
    by CRC Press

    380 Pages 194 B/W Illustrations
    by CRC Press

    The study of fracture mechanics of concrete has developed in recent years to the point where it can be used for assessing the durability of concrete structures and for the development of new concrete materials. The last decade has seen a gradual shift of interest toward fracture studies at increasingly smaller sizes and scales. Concrete Fracture: A Multiscale Approach explores fracture properties of cement and concrete based on their actual material structure.

    Concrete is a complex hierarchical material, containing material structural elements spanning scales from the nano- to micro- and meso-level. Therefore, multi-scale approaches are essential for a better understanding of mechanical properties and fracture in particular. This volume includes various examples of fracture analyses at the micro- and meso-level. The book presents models accompanied by reliable experiments and explains how these experiments are performed. It also provides numerous examples of test methods and requirements for evaluating quasi-brittle materials. More importantly, it proposes a new modeling approach based on multiscale interaction potential and examines the related experimental challenges facing research engineers and building professionals.

    The book’s comprehensive coverage is poised to encourage new initiatives for overcoming the difficulties encountered when performing fracture experiments on cement at the micro-size/scale and smaller. The author demonstrates how the obtained results can fit into the larger picture of the material science of concrete—particularly the design of new high-performance concrete materials which can be put to good use in the development of efficient and durable structures.

    Introduction—Why a New Book on Fracture of Concrete?
    Contents per Chapter
    Classical Fracture Mechanics Approaches
    Stress Concentrations
    Linear Elastic Fracture Mechanics (LEFM)
    Plastic Crack-Tip Model
    Fictitious Crack Model (FCM)
    Determination of FCM Parameters
    Mechanics Aspects of Lattice Models
    Short Introduction to Framework Analysis
    Equivalence between a Shell Element and a Simple Truss (Hrennikoff)
    Effective Elastic Properties of Beam Lattices
    Similarity between Beam Lattice Model and Particle Model
    Fracture Criteria
    Lattice Geometry and the Structure of Cement and Concrete
    Size/Scale Levels for Cement and Concrete
    Disorder from Statistical Distributions of Local Properties
    Computer-Generated Material Structures
    Material Structure from Direct Observation
    Lattice Geometry and Material Structure Overlay
    Local Material Properties
    Elastic Properties of Lattice with Particle Overlay
    Upper and Lower Bounds for the Young’s Modulus of Composites
    Effective Young’s Modulus of a Two-Phase Aggregate-Matrix Composite
    Effective Elastic Properties in Three Dimensions
    Fracture of Concrete in Tension
    Analysis of Uniaxial Tension Experiments
    Fracture Process in Tension
    Effect of Particle Density on Tensile Fracture
    Small-Particle Effect
    Boundary Rotation Effects and Notches
    Indirect Tensile Tests
    Brazilian Splitting Test
    Bending
    Combined Tensile and Shear Fracture of Concrete
    Tension and In-Plane Shear
    Biaxial Tension Shear Experiments
    4-Point-Shear Beam Test
    Anchor Pull-Out
    Torsion (Mode III Fracture)
    Compressive Fracture
    Mesomechanisms in Compressive Fracture
    Softening in Compression
    Softening as Mode II Crack-Growth Phenomenon
    Lattice Approximations
    Macroscopic Models
    Size Effects
    Classical Models Describing Size Effect on Strength
    Size Effect on Strength and Deformation: Experiments
    Lattice Analysis of Size Effect: Uniaxial Tension
    Lattice Analysis of Size Effect: Bending
    Damage Distribution in Structures of Varying Size
    Concluding Remarks
    Four-Stage Fracture Model
    Fracture Process in Uniaxial Tension
    Stage (0): Elastic Behavior
    Stage (A): (Stable) Microcracking
    Stage (B): (Unstable) Macrocracking
    Stage (C): Crack-Face Bridging
    Four Fracture Stages, yet a Continuous Process
    Similarity between Tensile and Compressive Fracture
    Ramification to Other Materials
    Multiscale Modeling and Testing
    Structure of Cement at the μm-Scale and Its Properties
    The Role of Water at the μm Scale
    F-r Potentials: From Atomistic Scale to Larger Scales
    Structural Lattice Approach
    Conclusions and Outlook
    Fracture Mechanisms
    Theoretical Models
    References
    Appendix 1: Some Notes on Computational Efficiency
    Appendix 2: Simple Results from Linear Elastic Fracture Mechanics
    Appendix 3: Stability of Fracture Experiments
    Appendix 4: Crack-Detection Techniques
    Appendix 5: Active and Passive Confinement
    Index

    Biography

    Jan G. M. van Mier received his engineering and Ph.D. degrees from Eindhoven University of Technology. After a postdoctorate year at the University of Colorado in Boulder, he moved to Delft University of Technology. As an associate professor at the Stevin Laboratory, in close cooperation with several Ph.D. students, he developed the Delft lattice model and conducted numerous experiments elucidating the fracture of concrete under a variety of conditions. In 1999, he was appointed "Antonie van Leeuwenhoek" professor at TU Delft, based on excellence in research, and developed and built the new microlab to immerse in fracture studies at smaller size/scales than before. In 2002, he moved to ETH Zurich as full professor and director of the Institute for Building Materials. In 2010, he became president of the International Association for Fracture Mechanics of Concrete and Concrete Structures (IA-FraMCoS).