Described is a method for restoring a cementitious system, the method having the following steps: a) securing a filling body provided with holes at a distance from the cementitious system to be restored, b) applying mortar to the cementitious system to be restored and to the filling body provided with openings, and c) introducing a cement containing an alkali storage system into the filling body provided with openings so that the cement containing an alkali storage system is in contact with the mortar. A corresponding cementitious system is also described.