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Author(s): O.H. Wallevik
Paper category: Symposium
Book title: 3rd International RILEM Symposium on Rheology of Cement Suspensions such as Fresh Concrete
Editor(s): O.H. Wallevik, S. Kubens, S. Oesterheld
ISBN: 978-2-35158-091-2
e-ISBN: 978-2-35158-092-9
Pages: V
Total Pages: 1
Language: English

It is a great honor for me to introduce the "RILEM International Symposium on Rheology of Cement Suspensions like Fresh Concrete" which is held jointly with the "18th Nordic Rheology Conference" on suspension rheology. These events are preceded by two courses (RILEM and NRS) on rheology, comprising a full week of rheology from 17th to 21st of August. The conference is an outcome of the RILEM technical committee 209-RFC; Rheology of cement based materials such as fresh concrete. I would like to use the opportunity to thank members of the committee in particular the secretary Dr. Mette Geiker. Also the Nordic Rheology Society (NRS) for consent to this joint venture. By combining the two conferences the participant will have a unique opportunity to explore different specific subjects since the RILEM participants will have access to the NRC conference and vice versa.

For cement based materials (concrete, mortar and cement paste) there is an increasing need for fundamental knowledge in order to control their rheological properties and their time and temperature dependence. Such properties determine the handling characteristics of the fresh concrete as well as its stability, i.e. the ability to prevent segregation. These are crucial issues at the building site. The need for fundamental rheological knowledge is obtrusive because of steadily increasing use of new materials such as blended multi-powder cements, fillers, various industrial by-products and a new generation of more effective plasticizing admixtures. New concrete types pose new demands; particularly SCC, which is concrete that can be placed in complicated formwork without any mechanical assistance.

One obstacle (that the conference will hopefully clarify) in the application of rheological science to concrete production process or science is that it has been difficult to quantify or measure accurately the rheological properties of the cement suspensions like concrete, as it gets so heterogenic during shearing. This is due to phenomena like dilatancy, particle migration and liquid transfer to the shearing zone as well as the plug formation in the expected shearing zone. In addition, it is always difficult to quantify the rate of shear for non-Newtonian fluid.

The aim with this conference is also to cast a new light on these topics and contribute to the fundamental understanding of the rheological properties of cement based materials. Such understanding will form the basis for a better control of these properties and thereby, improved effectiveness on the building site.

Rheology is by definition the science of flow and deformation of matter and is therefore ideal to evaluate the mobility of cement based particle suspensions, like the workability of fresh concrete. It is the hope of the chairman that the symposium will be fruitful, give better understanding of the subject and act as a driving force for more use of the science.

Professor Olafur H. Wallevik

Online publication: 2009
Publication Type: full_text
Public price (Euros): 0.00

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