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Chemo-mechanical characterization of hydrated calcium-hydrosilicates with coupled Raman- and nanoindentation measurements

Stemmermann, P.; Garbev, K.; Gasharova, B.; Beuchle, G.; Haist, M.; Divoux, T.

Abstract (englisch):
Celitement is a new type of cement that is based on hydraulic calcium-hydrosilicate (hCHS). It is produced by mechanochemical activation of Calcium-Silicate-Hydrates (C-S-H) in a grinding process. Due to the lack of typical clinker minerals, its CaO/SiO_{2} (C/S) ratio can be minimized from above 3 (as in Ordinary Portland Cement) down to 1, which significantly reduces the amount of CO_{2} released during processing. The reaction kinetics of hCHS differs from that of classical clinker phases due to the presence of highly reactive silicate species, which involve silanol groups instead of pure calcium silicates and aluminates and aluminoferrites. In contrast to Portland cement, no calcium hydroxide is formed during hydration, which otherwise regulates the Ca concentration. Without the buffering role of Ca(OH)_{2} the concentration of the dissolved species c(Ca^2+) and c(SiO_{4}^4−) and the corresponding pH must be controlled to ensure a reproducible reaction. Pure hCHS reacts isochemically with water, resulting in a C-S-H phase with the same chemical composition as a single hydration product, with a homogeneous distribution of the main elements Ca and Si throughout the sample. ... mehr

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DOI: 10.1016/j.apgeochem.2020.104582
Zugehörige Institution(en) am KIT Institut für Technische Chemie (ITC)
Institut für Beschleunigerphysik und Technologie (IBPT)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 07.2020
Sprache Englisch
Identifikator ISSN: 0883-2927
KITopen-ID: 1000119926
HGF-Programm 34.15.01 (POF III, LK 01)
Mineralische Konstruktionsmaterialien
Erschienen in Applied geochemistry
Band 118
Seiten 104582
Vorab online veröffentlicht am 30.05.2020
Schlagwörter Ramanspektroskopie; Nanoindentation; Celitement; CO2; nachhaltiger Zement; C-S-H
Nachgewiesen in Scopus
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