The IGF project 19901 N of VDZ gGmbH is 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.
Cement chemical optimisation of cements containing fly ash
In the planned project, various optimisation possibilities for cements containing fly ash are to be investigated and demonstrated. Up to now, the hydration reactions of hard coal fly ashes in cement have mainly been investigated against the background of the chemical composition of the hard coal fly ashes used. For the production of high-performance fly ash-containing cements in cement plants, however, further knowledge about the interaction of the fly ash used and the other components is of decisive importance. Various hard coal fly ashes are being intensively investigated focussed on the effects of different clinkers and sulphate carriers. Furthermore, the fineness of the components and the influence of mineral additives will be investigated.
In detail, the following will be investigated:
- how the variation of the particle size distribution of the clinker component influences the standard properties;
- how fly ash glasses of different composition can be characterized more precisely and effectively with regard to pozzolana reactivity by means of SEM/EDX characterization than by conventional chemical analysis;
- how strongly the clinker composition and late available sulphate influence the pozzolana reaction;
- incorporation of sulphate into the CSH or CASH phases formed by the fly ashes;
- how the variation in the amount of mineral additives added influences the reaction products and the standard properties;
- which factors promote synergies when mixing different types of coal fly ash.
Following completion of the research project, cement producers will be in a position to use the clinkers and fly ashes available more specific than before and to increase the performance of fly ash cements. Thus, small and medium-sized cement manufacturers in particular can improve their competitiveness in the market.