Ceramics-Silikáty 67, (1) 1 - 9 (2023) |
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ACTIVATION OF METAKAOLIN BY CaO And CaSO₄ ANHYDRITE II
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Škvára František 1, Šídlová Martina 1, Šulc Rostislav 2, Pulcová Klára 1
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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 Building Technology, Faculty of Civil Engineering, Czech Technical University in Prague, Jugoslávských partyzánů 1580/3, 160 00 Prague, Czech Republic
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Keywords: Metakaolin, Activation, Hydraulic binder, ROMAN cement, CaSO₄ anhydrite II
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The paper presented deals with the activation of metakaolin enabling the preparation of a new hydraulic binder. Activation of metakaolin is carried out using calcium oxide or hydroxide and gypsum or CaSO₄ in the form of anhydrite II. CaO and CaSO₄ anhydrite II were found to be more effective activators of metakaolin compared to Ca(OH)₂ and CaSO₄.2H₂O. The binding phase is represented here by an amorphous C-A-S-H phase accompanied with a C-S-H phase indicating similarity with Roman cement. Several crystalline hydrating products are present in the binder with ettringite being the major phase, and CaCO₃, Ca(OH)₂ and CaSO₄.2H₂O constituting its minor phases. In its composition, the binder, which is prepared synthetically, agrees with that of hydrated FBC ashes, and was found to be stable over a period of 2.8 years achieving strengths comparable to those of Portland cement. |
 PDF (3.0 MB) |
doi: 10.13168/cs.2022.0054
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