RILEM International Conference on Early Age Cracking in Cementitious Systems (EAC'01), Haifa, Israel, March 2001
Title: RILEM International Conference on Early Age Cracking in Cementitious Systems (EAC'01), Haifa, Israel, March 2001
Author(s): A. Bentur, K. Kovler
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
Publisher: RILEM Publications SARL
Issue date: 2001-08-01
Publication year: 2001
Pages: 446 - 446
Total Pages: 1
Abstract: The RILEM International Conference on Early Age Cracking in Cementitious Systems (EAC ’01)was held in Haifa,Israel,on March 12 to March 14,2001.
The conference was supported by the National Building Research Institute of the Technion, Israel Institute of Technology,the Israeli cement producer Nesher Israel Cement Enterprises Ltd.
and the Municipality of Haifa.
The conference was sponsored by the RILEM Technical Committee TC 181-EAS "Early Age Shrinkage Induced Stresses and Cracking in Cementitious Systems" and it brought together 70 participants, most of them outside of Israel.
The conference objective was to serve as a stage for the presentation of up-to-date research on early age cracking issue,which has resurfaced as a key issue in modern concrete technology.
This is largely the result of application of new means to control cracking (e.
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.
high strength concretes of low water/binder ratio,w/b).
To deal with this issue on the scientific and engineering level,there is 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 length changes.
This was clearly highlighted in the 35 papers presented in the conference,which addressed the issue from variety of points of view.
The discussion during the conference advanced our understanding of the significance of the synthesis of the various views.
The issue of early age cracking was addressed from five points of view:driving forces,engineering properties,analytical models,testing techniques and special cementitious systems.
The driving forces considered included thermal dilation and autogenous shrinkage.
A variety of points of view were considered,starting from the materials themselves,the type of cement and of concrete (such as self-compacting concrete) through analysis of internal restrains,as well as the influence of external conditions expressed in terms of the formworks and their removal.
The engineering properties relevant to the treatment of early age cracking were addressed in several papers.
The properties and issues highlighted were internal damage in the form of microcracks,the effect of shrinkage reducing admixtures and performances in repair materials.
Several analytical models were presented,dealing with a variety of issues that need to be quantified for a comprehensive approach to simulate and predict early age cracking:development of mechanical properties at early age,creep and relaxation,temperature and strain development in actual structures and an overall model to predict cracking,taking into account numerous inputs such as type of cement and insulation of the concrete.
Attention was given to testing techniques ,since it is quite evident that prevailing tests based on evaluation of free deformation are not sufficiently effective for assessing early age cracking risks.
The papers addressed the significance of volume and linear dimensional changes tests,the application of non-destructive tests to evaluate early age properties and cracking criteria under sustained loading in restrained conditions.
A bulk of 13 papers dealt with early age cracking in special compositions .
Several types of variables were covered by these papers:admixtures,blended cements,compositions characteristic to high strength low w/b ratio concretes, controlled low strength materials and concretes incorporating lightweight aggregates serving as internal curing agents.
Attention was also given to the influence of reinforcing bars,which induce internal restraint that may aggravate cracking but at the same time reinforce the concrete to mitigate cracking.
The papers presented in the conference covered the variety of points of view, which need to be addressed in order to develop a comprehensive approach to deal with early age cracking.
Lively discussions developed around some of the issues,covering a wide range of questions,from portland cement quality and production to concrete practices.
The conference clearly highlighted the trend in the research community to provide greater focus on issues of technological significance,based on fundamental scientific concepts,which are of need to the engineering community to solve problems of early age cracking.
Pre-proceedings were provided to the conference participants.
The final proceedings will be soon published by RILEM.
Online publication: 2001-06-27
Classification: RILEM Bulletin
Publication type : full_text
Public price (Euros): free
>> You must be connected to view the paper. You can register for free if you are not a member