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

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.

Supported by

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.

Contact

Dr. Jörg Rickert

Dr. Jörg Rickert

Phone:
+49-211-45 78-283

Fax:
+49-211-45 78-44427

Duration

08/2012 - 07/2014

Publications

Results (German)

Calcined clay as a pozzolanic cement constituent: Correct calcination of the clay also lowers the water demand and superplasticizer requirement of the cement

In: Cement International. 2016, 14(1), p. 21


Fly ash as a main constituent of cement – The residual coke has little effect on consistency and superplasticizer demand

In: Cement International 12 (2014) 3, p. 18

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

Herrmann, Jens; Rickert, Jörg

In: GDCh-Monographie Band 46, p. 457-460


Influence of fly ash cement on properties of fresh cement paste and on cement's interactions with superpasticizer

Herrmann, Jens; Rickert, Jörg

In: Zement i ego primenenie, 2017, 5, p. 66-70 (in Russian)


Influences of fly ash on rheological properties of fresh cement paste and oncement’s interactions with superplasticizers

Herrmann, Jens; Rickert, Jörg

In: Bauhaus-Universität Weimar (Hrsg): 19.Internationale Baustofftagung Tagungsbericht (Weimar 16.-18.09.2015). Weimar, 2015


Influences of clay's calcining conditions on rheological properties of cements with calcined clay and on interactions with superplasticizers

Herrmann, Jens; Rickert, Jörg

In: China Building Materials Academy (Hrsg.): 14th International congress on the chemistry of cement, ICCC (Beijing 13.-16.10.2015). Beijing, 2015


Influences of fly ash on rheological properties of cement paste and on cement interactions with superplasticizers

Herrmann, Jens; Rickert, Jörg

In: ALIT inform. 2016, (2-3), p. 14-25


Interactions between Cements with Calcined Clay and Superplasticizers

Herrmann, Jens; Rickert, Jörg

In: Malhotra, V.M.; Gupta, P.R.; Holland, T.C.: Eleventh International Conference on Superplasticizers and other chemical admixtures in concrete : Papers : Ottawa, Canada, July12-15, 2015: American Concrete Institute, ACI, 2015 (ACI Publication SP 302, p. 299-314


Thermally activated clays on a large scale: Burning conditions in laboratory furnace transferable to chamber furnace

In: Cement International. 2014, 12(1), p. 24


Workability of concrete made with fly ash cement: Particle size distribution and soluble sulfates in siliceous fly ash outweigh the effect of carbonic residue

In: Cement International. 2015, 13(5), p. 17-18