Report rep041 : Internal Curing of Concrete - State-of-the-Art Report of RILEM Technical Committee 196-ICC

Advances in concrete technology over the past several years have led to the practical use of concrete with a low water-binder ratio (w/b). Unfortunately, concretes with low w/b are prone to early age cracking unless special precautions are taken. The primary reason for that is auto-genous shrinkage, which is a phenomenon, which is ingrained in concrete of low w/b ratio.

Conventional curing procedures of ponding in water are not sufficiently effective to combat autogenous shrinkage in low w/b concrete. They may eliminate the autogenous shrinkage in small cross-sections only, because the penetration of water from the externally ponded surface is limited.

In view of these limitations, different strategies of shrinkage mitigation have been developed in recent years, based on special advanced internal methods of internal curing (IC) are cur-rently being intensively studied in research groups in several countries. These methods have been the focus of this State-of-the-Art report prepared by the RILEM Technical Committee TC-196 ICC 'Internal Curing of Concrete' in the years 2002 - 2007. The current report repre-sents a comprehensive and harmonized document covering the present knowledge about the principles, technologies and effects of internal curing of concrete.

After introducing the scope and limitation of work of TC 196-ICC , the report is organised in 8 different chapters: General concept and terminology / Mechanisms of internal water curing / Materials science-based models / Materials and methods for internal curing / Experimental methods to study internal water curing / Effect of internal curing on autogenous deformation / Effect of IC on other concrete properties. A last chapter is presenting the conclusions and outlook of the TC 196-ICC work.

Contents

Chapter 1 - Introduction

Chapter 2 - General concept and terminology

Chapter 3 - Mechanisms of internal water curing

Chapter 4 - Materials science-based models

Chapter 5 - Materials and methods for internal curing

Chapter 6 - Experimental methods to study internal water curing

Chapter 7 - Effect of internal curing on autogenous deformation

Chapter 8 - Effect of IC on other concrete properties

Chapter 9 - Benefits and case studies using internal curing of concrete

Chapter 10 - Conclusions and outlook