On hydration in the presence of calcium and sulfate ions, it forms the insoluble, fibrous mineral ettringite, which provides the strength in sulfoaluminate concretes, and/or monosulfoaluminate, and aluminium hydroxide.
When exposed to water containing calcium and sulfate ions, it forms the insoluble, fibrous mineral ettringite, which contributes to the strength of sulfoaluminate concrete and/or monosulfoaluminate and aluminum hydroxide.