Mechanically activated kaolin replacing metakaolin in alkali-activated cement formulation
This work provides in-depth research on alkali-activated binder formulations, employing mechanically activatedkaolin (K-MA) as a substitute precursor for metakaolin (MK). The potential of K-MA to replace MK was evaluated byconducting an extensive characterization of the alkali-activated cements (AAC...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/226011 |
| Acceso en línea: | https://hdl.handle.net/2445/226011 |
| Access Level: | acceso embargado |
| Palabra clave: | Reducció del diòxid de carboni Ciment pòrtland Impacte ambiental Minerals d'argila Caolí Carbon dioxide mitigation Portland cement Environmental impact Clay minerals Kaolin |
| Sumario: | This work provides in-depth research on alkali-activated binder formulations, employing mechanically activatedkaolin (K-MA) as a substitute precursor for metakaolin (MK). The potential of K-MA to replace MK was evaluated byconducting an extensive characterization of the alkali-activated cements (AACs). The structural analysis performedthrough Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA),<sup>27</sup>Aluminum magic angle spinning nuclear magnetic resonance (<sup>27</sup>Al MAS NMR), and scanning electron microscopy(SEM) revealed that K-MA enhances the amorphous nature and microstructural homogeneity of cements. The resultsdemonstrated that K-MA-based cements exhibit superior compressive strength than MK-based cements, especiallywhen sodium silicate (waterglass) was added, achieving values up to 42 MPa at 28 days. These findings suggest thatK-MA is a highly effective precursor for AACs formulation, as well as an alternative to replace MK. While thermalactivation (TA) processes for dehydroxylation are associated with significant CO<sub>2</sub> emissions, mechanical activation(MA) offers a more sustainable alternative by utilizing electrical energy, which can be derived from less pollutingrenewable sources. |
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