US Patent 9034098 Hydraulic binder with low clinker content

A hydraulic binder includes, in parts by mass: (a) from 20 to 60 parts of Portland clinker; (b) from 20 to 40 parts of slag; and (c) from 0 to 60 parts of inorganic material other than the clinker and the slag; the sum of (a), (b) and (c) being equal to 100 parts; which binder further includes a slag activator including, relative to 100 parts of the sum of (a) and (b): from 1.4 to 6.55 parts of alkali metal salt, expressed as equivalent-Na2O; and from 1.1 to 11.0 parts of calcium sulfate, expressed as SO3.