Hydraulic fixing agent that is based on Portland cement, a sulphate and
aluminum component that is usual in this system, and optionally other additives.
This is characterized in that, according to DIN 18156 (Part 2, Sec. 5.2.2.2, 5.2.2.3a)
and 5.2.2.4), the hydraulic fixing agent has (1) an adhesive pull strength of at
least approximately 0.15 N/mm2 when acted upon by water for 40 hours
and (2) an adhesive pull strength of at most approximately 0.10 N/mmyy2 when acted
upon by an aqueous sulphate solution and/or an aqueous solution of an aluminum
salt, each of which has a pH value of 12.5, for a period of 40 hours.