Understanding the rheological properties of fresh concrete, the hydration phenomenon of cement responsible for structuration, the relationship between the characteristics of the porous solid obtained and its mechanical performances or resistance to the aggressive penetration requires a complex knowledge of the physicochemistry of reactive porous materials. The development of simple formulation rules therefore requires the assimilation of this knowledge and a good command of the properties of these materials.
The purpose of this book is to provide the mix designer with useful knowledge on granular materials and porous materials, which will enable the innovative design of concrete. Topics covered include the characterization of granular materials, the concepts of porosity and specific surface area, and the transport properties (diffusion and permeation) of concrete. Some of these topics are already covered in other general books dedicated to granular or porous materials. The objective here is to bring them together in one book by adapting them for use by concrete specialists.
Applications in the form of exercises are offered at the end of each chapter to enable readers to assimilate the theoretical knowledge and to apply such knowledge to concrete problems encountered in civil engineering.
1. Description of Granular Materials, Definitions.
3. Specific Surface Area of Materials.
4. Voids in Granular Materials and the Arrangement of Grains.
5. Voids in Concrete.
6. The Fundamentals of Diffusion.
Jean-Pierre Ollivier is Emeritus Professor in Civil Engineering at INSA Toulouse, France. He has 40 years' experience in teaching building materials for Civil Engineers. The author of more than 150 research papers and 4 books on concrete technology, his main field of research is concrete durability and transport properties. Jean-Michel Torrenti is the head of the Materials department at IFSTTAR (French Institute of Science and Technology for Transport, Development and Networks) and is Professor at Ecole nationale des ponts et chausses, Paris, France. His research deals with the mechanical behavior of concrete, its durability and the coupled behavior. Myriam Carcass s is Professor at the University of Toulouse in France. Her main field of research is concrete durability and transport properties.
Introduction xi Chapter 1. Description of Granular Materials, Definitions 1 1.1. Introduction 1 1.2. Density 2 1.3. Porosity of granular material 4 1.4. Compactness 4 1.5. Void ratio 5 1.6. Relative compactness 6 1.7. Saturation point 7 1.8. Moisture content 7 1.9. Ratio between the different densities 12 1.10. Absorption of water 12 1.11. Bibliography 13 1.12. Exercises 13 Chapter 2. Granulometry 19 2.1. Introduction 19 2.2. Characterization of the shape of grains 21 2.3. Methods of granulometric analysis 22 2.4. Granularity: presentation of results 40 2.5. Granularity of a mixture of aggregate 46 2.6. Bibliography 47 2.7. Exercises 48 Chapter 3. Specific Surface Area of Materials 55 3.1. Definition 55 3.2. Calculating the specific surface area of a granular material 57 3.3. Methods based on permeability and porosity measurements 59 3.4. Methods based on the adsorption of a gas 70 3.5. Methylene blue test for the characterization of fine particles 78 3.6. Bibliography 79 3.7. Exercises 79 Chapter 4. Voids in Granular Materials and the Arrangement of Grains 87 4.1. Introduction 87 4.2. Sphere packing (one-dimensional: ? = 2R): theoretical approach and experimental data 88 4.3. Experimental data 95 4.4. Influence of grain shape 97 4.5. Search for maximum compactness 98 4.6. Bibliography 121 4.7. Exercises 121 Chapter 5. Voids in Concrete 129 5.1. Definitions 129 5.2. Characterization of heterogeneous materials 133 5.3. Specific surface area of porous solids 136 5.4. Measurements of the porosity of consolidated materials 139 5.5. Porometry 145 5.6. Bibliography 175 5.7. Exercises 177 Chapter 6. The Fundamentals of Diffusion 195 6.1. The basics of diffusion 195 6.2. Diffusion in porous media 219 6.3. Measurement of the effective diffusion coefficient in porous matter 228 6.4. The relationship between the effective diffusion coefficient and porous structure 245 6.5. Gaseous diffusion 256 6.6. Bibliography 262 6.7. Exercises 266 Chapter 7. Permeability 279 7.1. Introduction 279 7.2. Definition of the permeability of a material 280 7.3. Measurement of permeability 282 7.4. The relationship between permeability and porous structure 296 7.5. The drying of concrete 303 7.6. Physical parameters and performance-based approach 307 7.7. Bibliography 309 7.8. Exercises 312 Index 333