Use of calcium sulfate in an inorganic mortar system based on aluminous cement and ground-granulated blast-furnace slag to increase load values

A method for a chemical fastening of an anchor in a mineral substrate, with an inorganic mortar system, wherein the inorganic mortar system comprises:

• comprising
• calcium sulfate used,
• a curable aqueous-phase aluminous cement component A, and
• an initiator component B in aqueous-phase for initiating the curing process, component A further comprising:
• at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid and phosphonic acids, and
• water, and
• component B comprising:
• blocked ground-granulated blast-furnace slag,
• water, and
• optionally at least one mineral filler, and
• wherein the method comprises:
• introducing a borehole into a mineral substrate,
• mixing component A and component B to obtain a hardening aluminous cement composition,
• inserting this aluminous cement composition directly into the borehole,
• inserting and adjusting the construction element to be fastened, and
• allowing the aluminous cement composition to harden and set.