Dr Jörg Rickert
Compared to Portland cement, the water demand of cements with calcined clay may be higher. Thus, concrete produced using these cements with calcined clay may be stiffer and may require a superplasticizer. However, knowledge on influences of these cements on the workability of concrete and their interactions with superplasticizers is available to a relatively small extent only.
The aim of the research project is to determine interactions between superplasticizers and cements with calcined clay. It is determined how the proportion of calcined clay in the cement as well as the dosage of superplasticizer influences the rheological properties of fresh cement paste and concrete. In the foreground are influences of the calcining conditions of the clays on the workability of cements with calcined clay and on the effect of different superplasticizers as well as influences of the test temperatures (“summer”, “winter”).
The results of the project will give important information to cement producers to enhance the workability of cements with calcined clay. Concrete technologists will receive important information to choose the right superplasticizer for the particular concrete composition and the actual time of the year. Both factors contribute to prevent undesired reactions in concrete.