POLYCARBOXYLIC ACID TYPE WATER-REDUCING AGENT AND CONCRETE COMPOSITION USING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a concrete having a high strength exhibiting property by mixing and using a copolymer containing polyoxyethylene, maleic anhydride and phenyl groups, containing a specified number of mols of oxyethylene units per 1 mol carboxy group and having a specified molecular weight and a polycarboxylic acid copolymer having a specified molecular weight. ;SOLUTION: In a copolymer (A) having constituent units of formulae I, II and III, (n) is 10-60 and R is a 1-5C alkyl group. A copolymer (B) of formula IV is obtained by copolymerizing a polyoxyethylene monoallyl monomethyl ether and maleic anhydride and carrying out esterification with a polyoxyethylene monoallyl ether. The molecular weights of the copolymers A and B each 5,000-100,000. A polycarboxlic acid type water-reducing agent obtained by blending 30-120 pts.wt. copolymer B with 100 pts.wt. copolymer A is added by 0.1-1 pt.wt. (expressed in terms of solid) to 100 pts.wt. cement and the resultant mixture is kneaded with water, anhydrous gypsum, etc., in a mixer.;COPYRIGHT: (C)2000,JPO