Structure, microstructure and thermal stability characterizations of C3AH6 synthesized from different precursors through hydration

Abstract

In this paper, the influence of precursors (CA, C7A3Z, C12A7, C6SrA3Z, C7A2FZ and commercial calcium aluminate cement ‘Gorkal 70’) on the structure, microstructure and thermal stability characterizations of C3AH6 through hydration was investigated. The materials were characterized by X-ray diffraction, differential thermal analysis–thermogravimetric analysis–evolved gas analysis and scanning electron microscopy combined with energy-dispersive spectroscopy 24 h and 72 h after starting the hydration process. Results of investigation confirmed the influence of precursor on shape and grain size of C3AH6. The CaO/Al2O3 mass ratio of precursors before the hydration process affects the size of C3AH6 crystals: the higher the CaO/Al2O3 value, the larger the size of the crystals of C3AH6. Moreover, the presence of Sr and Fe affects the formation of stable C3AH6 crystals.