Synthesis and Characterization of Calcium Sulfoaluminate Hydrates-Ettringite (AFt) and Monosulfate (AFm).

The goal of the presented work was to find the most favorable conditions for the synthesis and stabilization of chemically pure ettringite and monosulfate. The reaction was carried out by mixing pure tricalcium aluminate (CA) and gypsum (CS¯H) in an excess amount of water. The impact of hydration time (2-7 days), CA:CS¯ molar ratio (1:1-1:3) and water vapor pressure of the selected drying agents (anhydrite-III and supersaturated CaCl solution) on the phase composition of the products was evaluated.

The Effect of Various Grinding Aids on the Properties of Cement and Its Compatibility with Acrylate-Based Superplasticizer.

The influence of grinding aids (pure triethanolamine and ethylene glycol) on the properties of cements, their compatibility with an acrylate-based superplasticizer and the rheological parameters of mortars were investigated. The presence of surfactants influences the standard properties of cements and the effectiveness of the superplasticizer. The results of the heat of hydration and setting time measurements indicate a delay in the hydration process and an increase in the induction period duration of the surfactant-doped pastes, in relation to the reference sample without grinding aids.

Implementation of Alternative Mineral Additives in Low-Emission Sustainable Cement Composites.

The influence of four naturally occurring mineral additives (zeolite, diatomite, trass and bentonite) on the hydration and properties of cement pastes and mortars was investigated. The materials change the phase composition, heat of hydration (determined by calorimetry) and mechanical properties of composites. After 28 days, the amount of Ca(OH) was reduced by up to 23% and up to 35% more C-S-H was formed, as proved by TG measurements.