Physical Properties of Concrete and Concrete Constituents

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

• ISBN13: 9781848213302
• ISBN10: 1848213301
• Edition: 1st
• Format: Hardcover
• Copyright: 2012-04-09
• Publisher: Wiley-ISTE

Summary

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.

Author Biography

Jean-Pierre Oliver 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 Torrent 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 Carcasss is Professor at the University of Toulouse in France. Her main field of research is concrete durability and transport properties.

Table of Contents

Introduction	p. xi
Description of Granular Materials, Definitions	p. 1
Introduction	p. 1
Density	p. 2
At the grain scale	p. 2
At the granular material scale	p. 4
Porosity of granular material	p. 4
Compactness	p. 4
Void Ratio	p. 5
Relative compactness	p. 6
Saturation point	p. 7
Moisture content	p. 7
Measurement of moisture content	p. 7
Comparison of methods of measurement	p. 10
Ratio between the different densities	p. 12
Absorption of water	p. 12
Bibliography	p. 13
Exercises	p. 13
Granulometry	p. 19
Introduction	p. 19
Characterization of the shape of grains	p. 21
Methods of granulometric analysis	p. 22
Sieving	p. 23
Granulometric methods based on sedimentation	p. 30
Coulter counter	p. 37
Laser granulometer (NF ISO 13320-1)	p. 38
Analysis of images coupled by microscopic observations	p. 39
Granularity: presentation of results	p. 40
Granular cumulative curves	p. 40
Granular frequency curves	p. 43
Other presentations of granularity	p. 43
Granularity of a mixture of aggregate	p. 46
Bibliography	p. 47
Exercises	p. 48
Specific Surface Area of Materials	p. 55
Definition	p. 55
The importance of this parameter Portland cement hydration	p. 56
Calculating the specific surface area of a granular material	p. 57
Power consisting of identical grains of known shape	p. 57
Homogeneous powder containing grains of non-uniform size	p. 58
Methods based on permeability and porosity measurements	p. 59
Kozeny-Carman equation	p. 59
Lea and Nurse apparatus	p. 65
Blaine apparatus	p. 67
Methods based on the adsorption of a gas	p. 70
Adsorption Kinetics	p. 70
Adsorption isotherms	p. 71
Determination of specific surface area from isotherm adsorption	p. 75
Determination of the specific surface area from an isotherm point	p. 77
Comparison of techniques	p. 78
Methylene blue test for the characterization of fine particles	p. 78
Bibliography	p. 79
Exercises	p. 79
Voids in Granular Materials and the Arrangement of Grains	p. 87
Introduction	p. 87
Sphere packing (one-dimensional: ¿ = 2R): theoretical approach and experimental data	p. 88
3D packing of square-based layers	p. 88
3D packing of rhombic-based layers	p. 90
Porosity of identical spherical packing	p. 90
Experimental data	p. 95
Influence of grain shape	p. 97
Search for Maximum compactness	p. 98
Mixture of two one-dimensional aggregates	p. 100
Theoretical analysis of the variation of compactness with volume fractions of grains of different sizes	p. 102
Model with interaction	p. 106
Consideration of the vibration, compressible packing model	p. 109
Mixture of three one-dimensional aggregates	p. 113
Bibliography	p. 121
Exercises	p. 121
Voids in Concrete	p. 129
Definitions	p. 129
Characterization of heterogeneous materials	p. 133
Specific surface area of porous solids	p. 136
Measurements of the porosity of consolidated materials	p. 139
Measurement of total porosity	p. 139
Measurement of open porosity	p. 142
Determination of closed porosity	p. 144
Porometry	p. 145
Mercury porosimetry (or Purcell porosimetry)	p. 145
Image analysis	p. 164
Method based on the adsorption of a gas	p. 165
Dynamic porosimeter: the Brémond porosimeter	p. 172
Thermoporometry	p. 172
Small angle X-ray scattering and small angle neutron scattering	p. 174
Innovative techniques in development	p. 175
Bibliography	p. 175
Exercises	p. 177
The Fundamentals of Diffusion	p. 195
The basics of diffusion	p. 195
Microscopic approach to diffusion	p. 195
Diffusion and transport of matter at the macroscopic level: Fick's first law	p. 201
A thermodynamic approach the molecular diffusion	p. 203
The diffusion of ions in solution	p. 205
Fick's second law	p. 210
The concentration profile of diffusing species	p. 211
Diffusion in porous media	p. 219
Molecular diffusion	p. 219
Ionic diffusion	p. 222
The penetration kinetic of a species by diffusion: Fick's second law	p. 222
Measurement of the effective diffusion coefficient in porous matter	p. 228
Diffusion cell method	p. 228
Electric field migration tests	p. 233
Measurement of the apparent diffusion coefficient by immersion	p. 240
Principle of methods of measuring the effective diffusion coefficient based on measurements of conductivity	p. 241
Orders of magnitude of the diffusion coefficient in concrete	p. 243
The relationship between the effective diffusion coefficient and porous structure	p. 245
Empirical models	p. 246
Polyphasic models	p. 249
Gaseous diffusion	p. 256
The diffusion of a gas in an infinite medium	p. 256
The diffusion of a gas in a pore	p. 258
The diffusion of a gas in a porous material	p. 259
The diffusion of a gas in a reactive porous environment	p. 261
Bibliography	p. 262
Exercises	p. 266
Permeability	p. 279
Introduction	p. 279
Definition of the permeability of a material	p. 280
Measurement of permeability	p. 282
Constant head permeameters	p. 282
Analysis of results: validity of Darcy's law	p. 286
Methods of measuring gas permeability	p. 294
Variable head permeameters	p. 295
The relationship between permeability and porous structure	p. 296
Empirical models	p. 297
Physical models	p. 297
The drying of concrete	p. 303
Physical mechanisms	p. 304
Simplified modeling of drying	p. 305
Physical parameters and performance-based approach	p. 307
Bibliography	p. 309
Exercises	p. 312
Index	p. 333
Table of Contents provided by Ingram. All Rights Reserved.