Set- and hardening accelerator

The accelerator contains at least one aluminum compound and at least one polymer. The monomer units of the polymer include at least acrylamide, methacrylamide and/or ethyenelic unsaturated compounds which carry a di-alkyl amino group or a tri-alkyl ammonium group. The aluminum compound is a complex and/or a salt of aluminum. The ligand or anion is one of sulfate, nitrate, nitrite, chloride, carboxylate, mixtures of carboxylates, phosphonates, phosphate, phosphites and mixtures of the ligands or anions. The carboxylate anion is formiate, acetate, glycolate, lactate, maleinate, citrate, tartrate, oxalate and/or malonate. The aluminum compound is a complex and/or salt of aluminum containing hydroxyl groups in addition to the anions. Further detailed lists of suitable polymers are provided. The mean molecular weight of the polymer is preferably 1000000 Daltons or more. It is soluble in water at a pH of 9, preferably a pH of 11-13. At least one aluminum compound and at least one polymer exist as a mixture. The accelerator is an aqueous solution, a suspension or powder. In aqueous solution or in a suspension, the aluminum is preferably at an Al 2O 3concentration of 6-20 wt% and the polymer concentration is 0.005-5 wt%, preferably 0.005-3 wt%. In powder form, the aluminum and polymer concentrations are preferably 15-60 wt% and 0.025-5 wt% respectively. The accelerator is used in a mixture or in a two-component system. Used as a two-component system, the aluminum compound(s) and polymer(s) are applied separately. Application is by wet spraying, dry spraying. Independent claims are included for the following: (A) the method of acceleration of bonding and/or hardening of cement; (B) and the concrete so produced. Die vorliegende Erfindung betrifft Abbinde- und Erhärtungsbeschleuniger zur Beschleunigung des Abbindens und Erhärtens von Zement und diesen enthaltenden Gemischen, wobei der Beschleuniger mindestens eine Aluminiumverbindung und mindestens ein Polymer enthält, wobei das Polymer als Monomereinheiten bzw. Monomereinheiten mindestens Acrylamid und/oder mindestens Methacrylamid und/oder mindestens ethylenisch ungesättigten Verbindungen, die eine Dialkylaminogruppe oder eine Trialkylammoniumgruppe tragen, enthält, sowie die Verwendung dieser Beschleuniger und ein Verfahren zum Beschleunigen des Abbindens und Erhärtens von Zement.