Composition of a cement additive material as an additive to cementitious mineral admixtures, and utilised as latent hydraulic binders to improve the outcome of cementitious products

摘要

. A composition of a cement additive material to improve durability of cementitious structures, is disclosed. The cement additive composition comprises an admixture of one or more of divalent magnesium metal silicates with capacity to act as a latent hydraulic binder in said composition activated by a hydration process under aqueous conditions, and in particular the divalent metal silicate is magnesium-dominated silicate, preferably comprising mineral groups of olivines, orthopyroxenes, amphiboles, talc and serpentines or mixtures thereof. The composition also comprise chloride ions or brine. Applications of the compositions are also disclosed, in particular to utilize a property of hydration as a major trigger for the latent hydraulic reaction of magnesium silicates, particularly for said olivines, when exposed to water and brines, in order to obtain a cementitious material becoming self healing.