Exploring Hydrous Carbonate-containing Brucite (HCB), the main phase in hydraulic reactive magnesium carbonate cements

• Applicant: Dr. Daniel Jansen
• Subject Area: Construction Material Sciences, Chemistry, Building Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 565860689

The proposed project aims to enhance understanding of the early hydration process in MgO/HCMs (Hydrated Magnesium Carbonates) blends, focusing on the strength-enhancing HCB (Hydrated Carbonated Brucite) phase. Using techniques such as calorimetry, in-situ XRD, 1H-TD-NMR, pore water analysis, elemental analysis, and Dissolved Inorganic Carbon analysis, the project will monitor early hydration and provide insights into the formation and structure of the HCB phase, including gel water and CO2 incorporation in interlayers of the phase. Rietveld refinement will study the early stages, evolution, and final composition of the HCB phase, assessing interlayer spacing related to H2O and CO2 integration. The project will investigate the effects of PCE (Polycarboxylate Ether) superplasticizers on the hydration and HCB phase formation of MgO/HY and MgO/nesquehonite blends, evaluating the influence of PCE molecules on dissolved ion mobility and the incorporation of H2O and CO2 into the interlayer of HCB phase. Thermal stability of the HCB phases will be analyzed using XRD, EA, TGA, and 1H-TD-NMR, examining changes in composition and structure with temperature and the retention of gel water and CO2. This project aims to provide a comprehensive dataset on the structural variability and composition of the HCB phase across different mixtures and temperatures, significantly contributing to the field of cementitious materials research.

• DFG Programme: Research Grants