Magnesian cements comprising a partially dehydrated magnesium salt and ahighly reactive magnesia, accelerated setting and enhanced water resistancemagnesian binders obtained from such cements and substance obtained withsuch a magnesian binder, non-expanded or expanded.

摘要

The invention relates to a magnesian cement. Said magnesian cementcomprises a magnesian salt, magnesia, to which setting water is added, andis characterised in that the magnesium salt is a partially hydratedmagnesium salt preferably having a mean hydration rate, expressed in watermolecules per magnesium salt molecule, between approximately 0 andapproximately 5, preferably between approximately 2 and approximately 4.With said cement, a water-based binder is produced wherein the relativeproportion of the magnesium salt, magnesia and water is defined by thedomain no. 1, preferably by the domain no. 2, of the ternary diagramMgO-MgCl2-H2O, or the domain No. 1 of the ternary diagram MgO-MgSO4-H2O.This gives a lower setting time (domain no. 1 for oxychloride oroxysulphate) and an enhanced moisture resistance (domain no. 2 foroxychloride binders).IMAGE