Early-age cracking is a challenge for the concrete industry. Materials selection, environmental conditions, and field practices all have considerable influence on the propensity for early-age cracking to occur. This document focuses on thermal- and moisture-related deformations; both are materials-related and contribute to early-age cracking. The document provides detailed reviews on the causes of deformation and cracking, test methods for assessing shrinkage and thermal deformation properties, and mitigation strategies for reducing early-age cracking. Keywords: autogenous shrinkage; cracking; early-age; heat of hydration; measurement; mitigation methods; microstructure; shrinkage; shrinkage cracking; sustainability; thermal cracking; thermal properties.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 3<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | CHAPTER 1\u2014 INTRODUCTION AND SCOPE 1.1\u2014 Introduction 1.2\u2014Scope CHAPTER 2\u2014 NOTATION AND DEFINITIONS 2.1\u2014 Notation <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | 2.2\u2014Definitions CHAPTER 3\u2014 CAUSES OF EARLY-AGE DEFORMATION AND CRACKING 3.1\u2014Thermal deformation <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 3.1.1 Influence of placement temperature 3.1.2 Influence of concrete mixture compositions 3.1.2.1 Aggregates <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 3.1.3 Cement types and sources 3.1.3.1 Cement content and fly ash <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 3.1.3.2 Slag cement 3.1.3.3 Air-entraining admixtures 3.2\u2014Autogenous shrinkage 3.2.1 Influence of water-cementitious material ratio <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 3.2.2 Influence of aggregate 3.2.3 Influence of supplementary cementitious materials <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 3.3\u2014Drying shrinkage 3.4\u2014Creep and stress relaxation from deformation restraint <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 3.5\u2014Mitigation of shrinkage CHAPTER 4\u2014 TEST METHODS AND ASSESSMENT 4.1\u2014Introduction 4.2\u2014Shrinkage measurements 4.2.1 Drying shrinkage <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4.2.2 Autogenous shrinkage <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4.3\u2014Ring test 4.3.1 Quantitative restrained ring tests 4.3.2 Stress development <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4.3.3 Quantifying effect of stress relaxation (creep) using ring <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4.3.4 Influence of moisture gradients <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 4.3.5 Influence of degree of restraint R 4.3.6 Influence of specimen geometry and bond between the concrete and steel 4.3.7 Effect of variable concrete wall thickness (eccentricity) 4.3.8 Cracking potential classification <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 4.3.9 Cracking potential envelopes 4.3.10 Developments for advancement of restrained ring analysis 4.3.10.1 Measurement variability 4.3.10.2 Dual ring <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 4.3.11 Summary of developments on ring test 4.4\u2014Rigid cracking frames 4.4.1 Test setup <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 4.4.2 Thermal stresses 4.4.3 Shrinkage deformation and stresses <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 4.4.4 Creep and stress relaxation <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 4.4.5 Degree of restraint 4.4.6 Summary of cracking frame test <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 4.5\u2014Coefficient of thermal expansion ( measurement <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 4.6\u2014Analysis tools assessing stresses and cracking 4.6.1 4C\u2013Temp&Stress software <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 4.6.2 High Performance Concrete Paving (HIPERPAV) software 4.6.3 MLS software <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | CHAPTER 5\u2014 SHRINKAGE CONTROL 5.1\u2014 Introduction 5.2\u2014Expansive additives <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 5.3\u2014Shrinkage-reducing admixtures 5.3.1 How SRAs work <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 5.3.2 Brief history of development of SRAs 5.3.3 Shrinkage-reducing chemical admixture materials 5.3.4 Application of SRAs 5.3.5 Shrinkage-reducing chemical admixtures and their impact on shrinkage and cracking <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 5.3.5.1 Influence of SRAs on autogenous shrinkage 5.3.5.2 Influence of SRA on plastic shrinkage <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 5.3.5.3 Influence of SRA on drying shrinkage 5.3.5.4 Overall shrinkage measurements for concrete containing SRA <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 5.3.6 Influence of SRA on shrinkage cracking <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 5.3.7 Influence of SRA on mechanical properties and durability 5.3.7.1 Mechanical properties of concrete containing SRA <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 5.3.7.2 Durability properties of concrete containing SRA <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | 5.4\u2014Internal curing 5.4.1 General 5.4.2 Lightweight aggregates 5.4.3 Superabsorbent polymers <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 5.4.4 Mixture proportioning for internal curing 5.4.5 Water movement during internal curing (X-ray microtomography) 5.4.6 Effect of internal curing on early-age shrinkage <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 5.4.7 Effect of internal curing on early-age strength <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | CHAPTER 6\u2014 REFERENCES 6.1\u2014 Referenced standards and reports <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 6.2\u2014Cited references <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" 231R-10 Report on Early-Age Cracking: Causes, Measurement and Mitigation<\/b><\/p>\n |