ISSN 0862-5468 (Print), ISSN 1804-5847 (online) 

Ceramics-Silikáty 66, (4) 453 - 461 (2022)


DEGRADATION OF A SULFOCALCIC BINDER IN A MIXTURE WITH CEMENT DUE TO FREEZING AND THAWING
 
Pulcová Klára 1, Šídlová Martina 1, Šulc Rostislav 2, Kohoutková Martina 3
 
1 Department of Glass and Ceramics, Faculty of Chemical Technology, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic
2 Department of Construction Technology, Faculty of Civil Engineering, Czech Technical University (CTU),Technická 2, 166 27 Prague, Czech Republic
3 Central laboratories, University of Chemistry and Technology, Prague,Technická 5, 166 28 Prague, Czech Republic

Keywords: Sulfocalcic Binder, FBC ash, Freeze-Thaw, Corrosion, Porosity, Ettringite
 

The paper deals with the freeze-thaw (F-T) resistance of pastes prepared from a mixture of Portland cement (CEM) and a new clinker-free calcium sulfate binder (SCB) based on sulfocalcic fly ash (FBC ash). Pastes with varying ratios of these two binders were prepared and their F-T corrosion resistance in water and a 3% NaCl solution was investigated. Furthermore, the paste aeration effect on the F-T resistance and the change in the phase composition of the paste during F-T cycling was studied. The results showed that the F-T resistance of the CEM-SCB mixtures was higher compared to the pastes prepared from the unmixed binders alone. All the mixed CEM-SCB pastes showed an undisturbed or slightly disturbed surface in both the water and 3% NaCl environments, i.e., excellent F-T corrosion resistance after 100 and 200 F-T cycles in an environmental test chamber. A change in the ettringite content over time was observed.


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doi: 10.13168/cs.2022.0041
 
 
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