Due to the high carbon footprint associated with the production of ordinary Portland cement, new binders are being developed to reduce carbon dioxide emissions during production. One such binder is the sulfoaluminate-belite clinker, with its main phases being calcium sulfoaluminate, belite, and ferrite. The purpose of this master thesis is to investigate how TiO2 affects the development of the clinker phases in the sulfoaluminate- belite clinker. For this purpose, a sulfoaluminate- belite cement clinker with the following desired phase composition was synthesised and cement was prepared: 65 % calcium sulfoaluminate, 25 % belite, and 10 % ferrite. Four different TiO2 contents (0.5; 1.0; 2.0; and 4.0 wt. %) were added to the cement clinker, which was then fired at four different temperatures (1150 °C, 1200 °C, 1250 °C, and 1300 °C). The phase composition of the clinker was determined using X-ray powder diffraction analysis and Rietveld method. The microstructure of the cement clinker and the chemical composition of the phases were investigated using scanning electron microscopy with energy-dispersive spectroscopy on selected clinker samples. Cement was prepared from the selected samples on which the specific surface area was determined using gas sorption and the particle size distribution by laser granulometry. We studied its reactivity by isothermal calorimetry and the compressive strengths were determined. It was found that the amounts of calcium sulfoaluminate and belite were relatively constant in all samples, while the amount of ferrite decreased with increasing TiO2 concentration in the sample, while the amount of perovskite increased. The amount of less represented phases increases with increasing TiO2 content of the sample, while the amount decreases with increasing temperature. Hydration occurs at the latest in the sample with the highest TiO2 content, while in the other four samples, hydration occurs at about the same time from the beginning of the measurement. The compressive strength is lower in samples with a higher amount of TiO2, which is most likely the result of the formation of non-reactive perovskite.
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