Physical Properties of Concrete and Concrete Constituents / Edition 1

by Jean-Pierre Ollivier, Jean-Michel Toorenti, Myriam Carcasses

Overview

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.

Contents

1. Description of Granular Materials, Definitions.
2. Granulometry.
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.
7. Permeability.

Product Details

ISBN-13:	9781848213302
Publisher:	Wiley
Publication date:	04/09/2012
Series:	ISTE Series , #596
Pages:	335
Product dimensions:	6.20(w) x 9.30(h) x 1.00(d)

About the Author

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 Carcassès is Professor at the University of Toulouse in France. Her main field of research is concrete durability and transport properties.

Table of Contents

Introduction xi

Chapter 1 Description of Granular Materials, Definitions 1

1.1 Introduction 1

1.2 Density 2

1.2.1 At the grain scale 2

1.2.2 At the granular material scale 4

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

1.8.1 Measurement of moisture content 7

1.8.2 Comparison of methods of measurement 10

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

2.3.1 Sieving 23

2.3.2 Granulometric methods based on sedimentation 30

2.3.3 Coulter counter 37

2.3.4 Laser granulometer (NF ISO 13320-1) 38

2.3.5 Analysis of images coupled by microscopic observations 39

2.4 Granularity: presentation of results 40

2.4.1 Granular cumulative curves 40

2.4.2 Granular frequency curves 43

2.4.3 Other presentations of granularity 43

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

3.1.1 The importance of this parameter Portland cement hydration 56

3.2 Calculating the specific surface area of a granular material 57

3.2.1 Power consisting of identical grains of known shape 57

3.2.2 Homogeneous powder containing grains of non-uniform size 58

3.3 Methods based on permeability and porosity measurements 59

3.3.1 Kozeny-Carman equation 59

3.3.2 Lea and Nurse apparatus 65

3.3.3 Blaine apparatus 67

3.4 Methods based on the adsorption of a gas 70

3.4.1 Adsorption Kinetics 70

3.4.2 Adsorption isotherms 71

3.4.3 Determination of specific surface area from isotherm adsorption 75

3.4.4 Determination of the specific surface area from an isotherm point 77

3.4.5 Comparison of techniques 78

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: Φ = 2R): theoretical approach and experimental data 88

4.2.1 3D packing of square-based layers 88

4.2.2 3D packing of rhombic-based layers 90

4.2.3 Porosity of identical spherical packing 90

4.3 Experimental data 95

4.4 Influence of grain shape 97

4.5 Search for Maximum compactness 98

4.5.1 Mixture of two one-dimensional aggregates 100

4.5.2 Theoretical analysis of the variation of compactness with volume fractions of grains of different sizes 102

4.5.3 Model with interaction 106

4.5.4 Consideration of the vibration, compressible packing model 109

4.5.5 Mixture of three one-dimensional aggregates 113

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

5.4.1 Measurement of total porosity 139

5.4.2 Measurement of open porosity 142

5.4.3 Determination of closed porosity 144

5.5 Porometry 145

5.5.1 Mercury porosimetry (or Purcell porosimetry) 145

5.5.2 Image analysis 164

5.5.3 Method based on the adsorption of a gas 165

5.5.4 Dynamic porosimeter: the Brémond porosimeter 172

5.5.5 Thermoporometry 172

5.5.6 Small angle X-ray scattering and small angle neutron scattering 174

5.5.7 Innovative techniques in development 175

5.6 Bibliography 175

5.7 Exercises 177

Chapter 6 The Fundamentals of Diffusion 195

6.1 The basics of diffusion 195

6.1.1 Microscopic approach to diffusion 195

6.1.2 Diffusion and transport of matter at the macroscopic level: Fick's first law 201

6.1.3 A thermodynamic approach the molecular diffusion 203

6.1.4 The diffusion of ions in solution 205

6.1.5 Fick's second law 210

6.1.6 The concentration profile of diffusing species 211

6.2 Diffusion in porous media 219

6.2.1 Molecular diffusion 219

6.2.2 Ionic diffusion 222

6.2.3 The penetration kinetic of a species by diffusion: Fick's second law 222

6.3 Measurement of the effective diffusion coefficient in porous matter 228

6.3.1 Diffusion cell method 228

6.3.2 Electric field migration tests 233

6.3.3 Measurement of the apparent diffusion coefficient by immersion 240

6.3.4 Principle of methods of measuring the effective diffusion coefficient based on measurements of conductivity 241

6.3.5 Orders of magnitude of the diffusion coefficient in concrete 243

6.4 The relationship between the effective diffusion coefficient and porous structure 245

6.4.1 Empirical models 246

6.4.2 Polyphasic models 249

6.5 Gaseous diffusion 256

6.5.1 The diffusion of a gas in an infinite medium 256

6.5.2 The diffusion of a gas in a pore 258

6.5.3 The diffusion of a gas in a porous material 259

6.5.4 The diffusion of a gas in a reactive porous environment 261

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

7.3.1 Constant head permeameters 282

7.3.2 Analysis of results: validity of Darcy's law 286

7.3.3 Methods of measuring gas permeability 294

7.3.4 Variable head permeameters 295

7.4 The relationship between permeability and porous structure 296

7.4.1 Empirical models 297

7.4.2 Physical models 297

7.5 The drying of concrete 303

7.5.1 Physical mechanisms 304

7.5.2 Simplified modeling of drying 305

7.6 Physical parameters and performance-based approach 307

7.7 Bibliography 309

7.8 Exercises 312

Index 333