HARDENING ACCELERATOR COMPOSITION FOR CEMENTITIOUS COMPOSITIONS

摘要

The invention concerns a process for the for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound, the reaction being carried out in the presence of an aqueous solution which contains a plasticizer suitable for hydraulic binders, characterized in that said reaction is being carried out in the presence of apatite and that the molar ratio of calcium to phosphor in the hardening accelerator is from 25/1 to 400/1.

主权项

1. Process for the preparation of a hardening accelerator composition, containing calcium silicate hydrate, by reaction of a water-soluble calcium compound, optionally calcium salt, with a water-soluble silicate compound, the reaction of the water-soluble calcium compound with the water-soluble silicate compound being carried out in the presence of an aqueous solution which contains a plasticizer suitable for hydraulic binders, selected from the group of (A) comb polymers, (B) polycondensates containing (I) at least one structural unit consisting of an aromatic or heteroaromatic moiety bearing a polyether side chain and (II) at least one structural unit consisting of an aromatic or heteroaromatic moiety bearing at least one phosphoric acid ester group, (C) lignosulphonates and/or (D) β-naphthalene sulphonate formaldehyde condensates (BNS), characterized in that the reaction of the water-soluble calcium compound with the water-soluble silicate compound is being carried out in the presence of apatite and that the molar ratio of calcium to phosphorus in the hardening accelerator is from 25/1 to 400/1.