The influence of different starting conditions to the hydrothermal formation of tobermorite - influence of silica source and water-to-solid ratio

The influence of different starting conditions to the hydrothermal formation of tobermorite - influence of silica source and water-to-solid ratio

Paper in proceedings (conference paper)

In this study, the influence of different starting materials, especially the silica source was studied. Hydrothermal reactions were performed at 180 °C under saturated steam pressure, while the reaction time was three days and C/S ratio of the starting mixture was set to 0.83. For the synthesis of tobermorite, the crystalline silica source with finer particles is favourable. After three days of reaction using silica sand Dorsilit (d50 = 5.3 µm) and w/s ratio in the range 2–5 ml/g tobermorite is the main detected phase in the samples. When amorphous silica sources (industrially prepared micro silica and self-synthesised SixOyOHz from TEOS) were used as starting materials, other C–S–H phases like gyrolite, hillebrandite and clinotobermorite were prepared.

In this study, the influence of different starting materials, especially the silica source was studied. Hydrothermal reactions were performed at 180 °C under saturated steam pressure, while the reaction time was three days and C/S ratio of the starting mixture was set to 0.83. For the synthesis of tobermorite, the crystalline silica source with finer particles is favourable. After three days of reaction using silica sand Dorsilit (d50 = 5.3 µm) and w/s ratio in the range 2–5 ml/g tobermorite is the main detected phase in the samples. When amorphous silica sources (industrially prepared micro silica and self-synthesised SixOyOHz from TEOS) were used as starting materials, other C–S–H phases like gyrolite, hillebrandite and clinotobermorite were prepared.

silica source, tobermorite, hydrothermal synthesis

silica source, tobermorite, hydrothermal synthesis

GALVÁNKOVÁ, L.; BARTONÍČKOVÁ, E.; OPRAVIL, T.

2020

16.09.2019

Research Institute of Binding Materials Prague

Praha

15th International Congress on the Chemistry of Cement (ICCC 2019) Congress proceedings – Papers and Posters Proceedings

first edition

2523-935X

5th International Congress on the Chemistry of Cement (ICCC 2019) Congress proceedings – Papers and Posters Proceedings

Czech Republic

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The influence of different starting conditions to the hydrothermal formation of tobermorite - influence of silica source and water-to-solid ratio