A concrete composition of the concrete is obtained with high strength in the case of a varying density, a method for the preparation of the composition and the concrete, and use of an anionic addition

摘要

PCT No. PCT/EP97/01682 Sec. 371 Date Feb. 4, 1998 Sec. 102(e) Date Feb. 4, 1998 PCT Filed Apr. 4, 1997 PCT Pub. No. WO97/39992 PCT Pub. Date Oct. 30, 1997An aqueous concrete mixture having an air pore volume between 10 and 85%, preferably between 20 and 85%. When the aqueous concrete mixture is cured, a concrete having uniform density and high strength is obtained. This is achieved by including in the concrete mixture an aqueous, anionic surface-active compound containing two sulphonic acid groups of the general formula(R)m-R1-(SO3M)2(1)wherein R is an aliphatic group having 4-20 carbon atoms, m is a number 1 or 2, the sum of the number of carbon atoms in the 1 or 2 R groups being 6-30, R1 is an aromatic group containing at least 2 aromatic rings and 10-20 carbon atoms, and M is a cation or hydrogen. The anionic compound has an air-entraining effect and improves the homogeneity of the concrete mixture.