GB1495811A - Method for the manufacture of concrete articles - Google Patents

Abstract

1495811 Concrete article ALFONG BETONGHARDNINGSMEDEL & CO KOMMANDITBOLAG AB 13 March 1975 [14 March 1974 1 April 1974] 10614/75 Headings C1H and C1A [Also in Division C4] Concrete articles are made by mixing cement, water and filler material to form a concrete mixture, adding to the concrete mixture a stable suspension of finely divided silica in a liquid containing a lyotropic liquid crystalline phase as a suspension stabilizer in an amount such that the silica is present in an amount of from 0À01 to 10 wt. per cent of the cement, stirring the concrete mixture so as to effectively distribute the silica and lyotropic liquid crystalline phase throughout the concrete mixture, moulding the concrete mixture and allowing it to harden. The cement may be portland cement or aluminate cement. The silica may have a particle size less than 10 microns and may be added as a colloidal solution. The suspension may be aqueous and contain up to 90 wt. per cent water, 10 to 80 wt. per cent silica particles as well as 0À001 to 80 wt. per cent surface active substance and 0-20 wt. per cent of an amphiphilic substance and/or hydrocarbon forming in the water phase a lyotropic liquid crystalline phase. The surface active substance may be sodium lauryl sulphate or nonyl phenyl polyethylene oxide glycol ether. The amphiphilic substance may be a carboxylic acid, alcohol, monoglyceride, phosphate, aldehyde, amine or an alkyl glycol ether having less than 3 ether groups. The hydrocarbon may be benzene, hexane or p-xylene. The surface of the concrete article may be made more durable and hydrophobic by being treated with a polymer (e.g polyurethane or silicon polymers or copolymers thereof). In examples, into concrete mixtures comprising cement, gravel and macadam were stirred additives comprising water, aryl glycol ether, silica (0À1 to 1 micron, about 0À1 micron or colloidal in size) and also, in most examples, pxylene. The concrete mixture of Example 14 also contained a lignosulphonate, red pigment and a red liquid paint.