Influence of Fe2O3 on the hydration kinetics of tricalcium aluminate

The influence of Fe2O3 on the hydration kinetics of tricalcium aluminate (C3A) was studied in order to clarify the mechanism of improving hydration resistance of CaO by in-situ synthesized tricalcium aluminate. The Krstulovic-Dabic model was used to investigate the hydration processes of Fe2O3-C3A solid solution and calculate the corresponding kinetic parameters. The hydration products were analyzed by the X-ray diffraction and scanning electron microscope. The results indicated that the Krstulovic-Dabic model simulated the hydration processes of Fe2O3-C3A solid solution at different stages effectively. The hydraulic activity of Fe2O3-C3A solid solution decreased with the addition of Fe2O3. Reasonable amount of Fe2O3 addition reduced the hydration rate in the initial stage of Fe2O3-C3A solid solution hydration, while the hydration rate of Fe2O3-C3A solid solution was increased with excessive amount Fe2O3. The hydration process was controlled by multiple mechanisms due to an incomplete layer of hydration products was formed on the surface.