Publications

Report rep025 : Early Age Cracking in Cementitious Systems - Report of RILEM Technical Committee 181-EAS - Early age shrinkage induced stresses and cracking in cementitious systems


Title: Early Age Cracking in Cementitious Systems - Report of RILEM Technical Committee 181-EAS - Early age shrinkage induced stresses and cracking in cementitious systems
Edited by A. Bentur
ISBN: 2-912143-33-0
e-ISBN: 2912143632
Pages: 350
Publication date: 2003

Early age cracking sensitivity is a well-known phenomenon, which is associated with drying shrinkage. In special structures and concretes this can be aggravated by thermal effects. The cracking sensitivity induced by drying can occur before or at the onset of setting (plastic shrinkage cracking) or at the period of few days after beginning of setting and hardening.
The advent of modern concrete technology renewed the interest in this issue from several points of view: application of new means to control cracking (e.g. fiber reinforcement and shrinkage reducing admixtures) and the development of a variety of new concretes of superior performance in the fresh and hardened state, that may be more sensitive to early age cracking (e.g. high strength concretes of low water/binder ratio).
In order to optimize the use and design with such concretes and admixtures, there is a need for a comprehensive understanding and treatment of early age cracking. Such an approach is much more complex than the simplistic treatment where cracking sensitivity is quantified in terms of free shrinkage only. It is essential to evaluate, test and model the systems under restrained conditions, to take into account the stresses developed and assess the risk of cracking by considering fracture criteria.
With this in mind, the RILEM technical committee TC 181-EAS was established, to develop and advance the required comprehensive treatment outlined above, to cover basic mechanisms, engineering and design considerations, as well as testing procedures. The present report is a compilation of the State of the Art produced by the committee, addressing the basic scientific principles and upon them expands the treatment towards various engineering aspects. The State of the Art covers a variety of topics required for a comprehensive treatment of early age cracking risks and their mitigation: driving forces and microstructural aspects, engineering properties, modeling, testing and implementation of the concepts in special cementitious systems.


Contents


Authors
Author(s): RILEM TC 181-EAS
Pages: XII - XII

Preface
Author(s): A. Bentur
Pages: XI - XI

Chapter 1: Introduction: Overview of early age cracking


Overview of early age cracking
Author(s): A. Bentur
Pages: 1 - 11

Chapter 2: Terminology and definitions


Terminology and definitions
Author(s): A. Bentur
Pages: 13 - 15

Chapter 3: Driving forces and microstructural aspects


Overview of driving forces
Author(s): D. Lange
Pages: 19 - 20

Chemical shrinkage
Author(s): L. Barcelo
Pages: 21 - 25

Evolution of solid behavior
Author(s): J. Bisschop
Pages: 27 - 36

Early thermal changes
Author(s): D. Lange, S.A. Altoubat
Pages: 37 - 38

Hydration and moisture distribution
Author(s): V. Baroghel-Bouny
Pages: 39 - 45

Drying shrinkage cracking at early ages
Author(s): J. Bisschop
Pages: 47 - 55

Early age creep
Author(s): D. Lange, S.A. Altoubat
Pages: 57 - 62

Chapter 4: Engineering properties


Autogenous and thermal deformations
Author(s): ě. Bj°ntegaard, E.J. Sellevold
Pages: 65 - 88

Shrinkage of concrete
Author(s): B. Persson
Pages: 89 - 99

Short term mechanical properties
Author(s): G. De Schutter, K. Kovler
Pages: 101 - 109

Visco-elastic response
Author(s): G. De Schutter, K. Kovler
Pages: 111 - 120

Thermal properties
Author(s): G. De Schutter
Pages: 121 - 125

Early age kinetics: Activation energy, maturity and equivalent age
Author(s): L. D'Aloia
Pages: 127 - 148

Chapter 5: Modeling concepts


Microstructural models
Author(s): J.-P. Charron, J. Marchand, B. Bissonnette, M. Pigeon
Pages: 151 - 168

Modeling of autogenous shrinkage
Author(s): S. Zhutovsky
Pages: 169 - 178

Empirical models describing the behavior of concrete at early age
Author(s): J.-P. Charron, J. Marchand, B. Bissonnette, M. Pigeon, B. Gerard
Pages: 179 - 192

Chapter 6: Testing


Experimental determination of the 'Time Zero', t0 ('Maturity-Zero', M0)
Author(s): J. Weiss
Pages: 195 - 206

Measurement methods for testing of early age autogenous strain
Author(s): T. A. Hammer
Pages: 207 - 215

Determination of the coefficient of thermal expansion
Author(s): C. Boulay
Pages: 217 - 224

Chemical shrinkage and internal relative humidity tests
Author(s): B. Persson
Pages: 225 - 240

Early age cracking tests
Author(s): A. Bentur
Pages: 241 - 255

Early age creep and stress relaxation tests
Author(s): W. Hansen
Pages: 257 - 265

Field monitoring of the early-age performance of concrete structures
Author(s): D. Cusson
Pages: 267 - 281

Chapter 7: Special cementitious systems


Very high strength concrete
Author(s): ě. Bj°ntegaard, E.J. Sellevold
Pages: 285 - 294

Internally cured concrete
Author(s): A. Bentur, K. van Breugel
Pages: 295 - 305

Fiber reinforced concretes
Author(s): A. Bentur
Pages: 307 - 314

Shotcrete
Author(s): M. Jolin
Pages: 315 - 322

Admixtures for reducing shrinkage and cracking
Author(s): J. Weiss, N. Berke
Pages: 323 - 335