Activated pulverised glass as an additive for mortars and cement, and related cementitious products

A cementitious composition suitable to form mortars or concretes including at least one hydraulic binder, water, optionally one or more aggregates, and comprising activated glass particles as an addition to mitigate an alkali-aggregate reaction, wherein a mitigation effect of the alkali-aggregate reaction is improved by activated glass particles obtained by firstly grinding to pulverization with an average diameter ranging from 10 and 200 micron, and an activation step consists of a subsequent washing of the grinded glass particles with fresh water that is renewed before it is saturated by the release of alkali into water by the finely subdivided glass, wherein the glass particles after grinding and washing with water have a ratio A between the specific surface SSBET, expressed in m2/g, and the laser specific surface Sv, expressed in m2/cm3, by the density, r, expressed in g/cm3, defined as activation parameter A=SSBET[m2/g]/Sv[m2/cm3]. ρ[g/cm3], in a range from 1.9 to 4.0.