Hydration of CAC pastes at high temperature

Calcium aluminate cements or CACs are of great interest in a wide range of areas, such as industrial applications, waste encapsulation and even restoration of heritage sites. The hydration products of CAC are known to vary as a function of temperature and humidity conditions. In this study, the hydration process of a CAC cured at 70°C under high humidity conditions and different water/cement ratios has been investigated. The aim of using these conditions was to directly obtain katoite-type cubic hydrates, together with the development of gibbsite. The different water/cement ratios used have given rise to different proportions of crystalline and amorphous hydrated phases. The percentages of hydration products formed have been identified and quantified in relation to the mechanical strength and porosity of the pastes at different curing ages. The stability of the pastes subjected to two curing conditions, under water and in laboratory conditions, for 2 years, has also been studied