Use of a naphthalenesulfonic acid polycondensate as a plasticizer in a construction composition and construction composition

Abstract

A naphthalenesulfonic acid polycondensate is used as a plasticizer in a construction composition comprising sand and at least one cementitious binder. The naphthalenesulfonic acid polycondensate is obtainable by a condensation reaction of i) a naphthalenesulfonic acid, ii) an alkoxylated hydroxyaryl compound having a polyoxyalkylene chain with 3 to 130 oxyalkylene units, and iii) formaldehyde, in a weight ratio of i):ii) of 95:5 to 60:40, preferably 95:5 to 75:25, more preferably 95:5 to 85:15, wherein the sand has a methylene blue value according to DIN EN 933-9 of at least 10 g/kg. The naphthalenesulfonic acid polycondensate is largely clay-insensitive and its dispersibility is independent of the quality of the sand.

Dependencies are inferred from the claim text.