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Background and goals of the research project

Blended cements offer various technical, economic and ecological benefits. Recently, cements with siliceous fly ash are being produced in Germany. Calcined clay is also suitable to reduce the clinker content of cement. To be able to establish cements with fly ash in the German market and to introduce cements with calcined clay into it, also their influences on rheological properties of fresh concrete as well as on the effects of superplasticizers must be known. Knowledge on this was available to a small extent only.

It was determined how the rheological properties and the consistency of fresh concrete can be improved by the adjustment of the type and proportion of fly ash or calcined clay in the cement to the clinker as well as the type and dosage of the superplasticizer. Influences of the particle size distribution, the content of residual coke and various processing parameters of fly ash as well as influences of the mineralogical composition of the clay and the calcining conditions were in the foreground of the investigations. The model on the action mechanisms of superplasticizers was extended for cements with fly ash or calcined clay.

Sponsors

The IGF project 16726 N of VDZ gGmbH was supported by the AiF within the framework of Industrial Collective Research (IGF) of the Federal Ministry of Economic Affairs and Energy on the basis of a decision of the German Bundestag.

Results (German): Interactions between siliceous fly ash or calcined clay as cement main constituent and superplasticizers based on polycarboxylate ether as well as their influences on rheological properties of fresh cement paste and fresh concrete

It was determined how the rheological properties and the consistency of fresh concrete can be improved by the adjustment of the type and proportion of fly ash or calcined clay in the cement to the clinker as well as the type and dosage of the superplasticizer.

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Person to contact

Haben Sie Fragen zu diesem Projekt?

Dr Jörg Rickert
Chemistry and mineralogy

+49-211-45 78-283
zch@vdz-online.de

Other items of possible interest

01.12.2008

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Related literature

Influences of fly ash and slag on cement-superplasticizer-interactions

[Translate to English:] In: GDCh-Monographie Band 48, S.96-99

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