New insights into the hydration of cementitious materials based on magnesium carbonates

The hydration of reactive periclase (MgO) in the presence of hydromagnesite (Mg5(CO3)4(OH)2·4H2O) was investigated by a variety of physical and chemical techniques. This system is of potential interest as low CO2 binder, if the magnesium carbonate is produced by carbonation from naturally occurring magnesium silicates such as olivine or serpentine. In contrary to thermodynamic prediction not artinite (Mg2(CO3)(OH)2·3H2O), but a very poorly-crystalline form of brucite (Mg(OH)2), and an unknown amorphous hydrate which partially loses its crystal water at about 100°C were the main hydration products