## Hydraulic reactivity and cement formation of baghdadite

Please always quote using this URN: urn:nbn:de:bvb:20-opus-259457
• In this study, the hydraulic reactivity and cement formation of baghdadite (Ca$$_{3}$$ZrSi$$_{2}$$O$$_{9}$$) was investigated. The material was synthesized by sintering a mixture of CaCO$$_{3}$$, SiO$$_{2}$$, and ZrO$$_{2}$$ and then mechanically activated using a planetary mill. This leads to a decrease in particle and crystallite size and a partial amorphization of baghdadite as shown by X-ray powder diffraction (XRD) and laser diffraction measurements. Baghdadite cements were formed by the addition of water at a powder to liquid ratio of 2.0In this study, the hydraulic reactivity and cement formation of baghdadite (Ca$$_{3}$$ZrSi$$_{2}$$O$$_{9}$$) was investigated. The material was synthesized by sintering a mixture of CaCO$$_{3}$$, SiO$$_{2}$$, and ZrO$$_{2}$$ and then mechanically activated using a planetary mill. This leads to a decrease in particle and crystallite size and a partial amorphization of baghdadite as shown by X-ray powder diffraction (XRD) and laser diffraction measurements. Baghdadite cements were formed by the addition of water at a powder to liquid ratio of 2.0 g/ml. Maximum compressive strengths were found to be ~2 MPa after 3-day setting for a 24-h ground material. Inductively coupled plasma mass spectrometry (ICP-MS) measurements showed an incongruent dissolution profile of set cements with a preferred dissolution of calcium and only marginal release of zirconium ions. Cement formation occurs under alkaline conditions, whereas the unground raw powder leads to a pH of 11.9 during setting, while prolonged grinding increased pH values to approximately 12.3.