JPH05238796

PURPOSE:To provide the cement admixture effective for improving the dispersibility, suppressing a slump loss and improving strength and durability to a cement compsn, by consisting this admixture of a copolymer of a polyalkylene glycol diester monomer having an unsatd. bond and an acrylic acid-based monomer and/or the metal salt thereof. CONSTITUTION:This cement admixture consists of the copolymer of (1) the polyalkylene glycol diester monomer having the unsatd. bond and (2) the acrylic acid-based monomer and/or the metal salt of this copolymer. The monomer (1) is exemplified by the monomer of formula I and the monomer (2) is exemplified by the monomers of formulas II and III. In the formulas I to III, R , R , R , R denote hydrogen, methyl group, (CH2)m3COOM , etc.; AO denotes 2 to 3C oxyalkylene group; m1-3 denote an integer from 0 to 2; n1 denotes an integer from 3 to 500; M denotes hydrogen, univalent metal, amino group, etc.; R R denote hydrogen, methyl group; X denotes a univalent metal, ammonium group, amino group, etc.; X denotes a bivalent metal.