Tagungsband zum 25. Workshop und Kolloquium "Rheologische Messungen an Baustoffen",

2. und 3. März an der Ostbayerischen Technischen Hochschule Regensburg

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Tagungsband zum 26. Workshop und Kolloquium "Rheologische Messungen an Baustoffen",

21. und 22. Februar 2017 an der Ostbayerischen Technischen Hochschule Regensburg

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Tagungsband zum 27. Workshop und Kolloquium, "Rheologische Messungen

an Baustoffen 2018"

7. und 8. März an der OTH Regensburg

Einige Beiträge sind in Englischer Sprache verfasst.

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Rheological measurements help to optimize the robust application of building materials. For the past few years applied rheology has been moving increasingly into the center of attention of the civil engineering society. Advanced testing equipment, intensive research and development work have all helped to deepen the understanding of this field. Last but not least, different conferences, such as the 28th Conference on the Rheology of Building Materials at the OTH, have helped to exchange the findings and establish valuable new contacts. Finding a compromise between rheological theory and its practical application has been the main topic of these 28 conferences.

In these proceedings important rheological topics are addressed: specific applications of concrete such as self-compacting concrete, tremie concrete and sprayed concrete and mortar mixes for 3D printing, which all may be classified as self-compacting concretes. The consideration of time- and temperature-dependent changes in workability are essential for a successful application of these materials. Furthermore, the influence of the mixing energy used and the way of casting/spraying is of high importance for the rheological properties. The rheology of other concrete types is drastically changed due to the compaction by vibrators.

Concrete rheology is controlled by its paste content and the rheology of the paste. Tests on pastes are easier to perform, as particle migration of aggregates is not present. However, one has to ask whether it is sufficient to use the results from the paste-measurements for the assessment of concrete and how the optimized paste content will be predetermined. The other question is which admixtures or additives may help to improve the very different application processes. Apart from using superplasticizer and stabilizers, entrained air is a powerful tool to influence rheology.

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The art of rheological measurements for construction materials was until 50 years ago a totally unknown territory. Even today it is often hard to understand,

unless you are an expert in the field. There are many people who buy the costly equipment for rheological measurements. However, they often find after some

time that the test set up, numerous influencing factors and the proper interpretation of the results is not that easy to work out. As a consequence this expensive

equipment ends up lying in the corners of the labs gathering dust. This conference and workshop on the “Rheology of Building Materials” in Regensburg

cannot solve all these problems. It, however, supplies a platform for excellent presentations of recent research work as well as demonstrations of useful equipment and exchange of ideas.

The proper workability of materials bound by mineral binders is essential for an economic production and for a perfect performance in hardened state. The papers

in these proceedings show examples of enhanced testing and applications.

These proceedings address important rheological topics:

· Inline control of ready mix concrete

· Tests on concrete and mortar for different purposes (e.g. rheology of calcium-sulfoaluminate mortars, of alkali activated binders, of mortars for 3D-printing)

· The influence of fibres on injecting mortars

· Oscillatory measurements.

The papers on mineral materials are enhanced with a special contribution on the behaviour of granular frazil ice. Hopefully, the reader will enjoy these papers

and get a lot of inspiration as well as some new ideas for her/his own work.

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