Cements magnesians comprising a magnesium salt partially hydrated, and a magnesia powders very reactive, binders magnesians has taken accelerated and a resistance to water improved obtained on the basis of such cements, and the material obtained with such a binder magnesian, which is not expanded or expands

摘要

The invention relates to a magnesia cement. / p & & p & this magnesia cement comprises a magnesium salt, magnesia, to which water is added, and is characterized in that the magnesium salt is a magnesium salt partially hydrated, preferably having a degree of hydration, expressed in the molecules of water per molecule of magnesium salt, preferably between about 0 and about 5, preferably between about 2 and about 4. / p & & p & with this cement, a hydraulic binder, the relative proportion of the magnesium salt, magnesia, and the water is defined by the field ndegre (s) 1, preferably by the field ndegre (s) 2, of the ternary diagram mgo - mgcl2 - h2 o, fig. 1 or the field ndegre (s) 1 of the ternary diagram mgo - mgso4 - h2 o, fig. 2). / p & & p & it is thus obtained a setting time is reduced (field ndegre (s) 1 for oxychloride or oxysulfate) and a better resistance to moisture (field ndegre (s) 2 to the binders oxychrlorures).