Acceleration of OPC by CAC in binary and ternary systems: The role of pore solution chemistry
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), GeoZentrum Nordbayern, Mineralogy, Schlossgarten 5a, 91054 Erlangen (Germany)
- Kerneos Research Center, 1 Rue le Chatelier, 38090 Vaulx-Milieu (France)
In dry-mortar-formulations calcium aluminate cement (CAC) is often used as a set accelerator for ordinary Portland cement (OPC). However, a critical amount of CAC is able to delay not only the silicate reaction but also the renewed C{sub 3}A dissolution of an OPC. This delay can be counteracted by adding an appropriate amount of calcium sulfate (C$) to the mix OPC/CAC. The initial hydration period is dominated by fast ettringite formation from CA (CAC) and CaSO{sub 4} from OPC generating early strength. High aluminum and low calcium concentrations in the pore solution probably hinder C-S-H seeding and precipitation, thus preventing alite dissolution. Aluminum has to be initially removed by precipitating hydrate phases to change the pore solution chemistry. The start of the silicate reaction is then induced by increasing the calcium concentration in the pore solution.
- OSTI ID:
- 22806480
- Journal Information:
- Cement and Concrete Research, Vol. 107; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
- Country of Publication:
- United States
- Language:
- English
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