| 摘要 |
PCT No. PCT/JP97/02095 Sec. 371 Date Feb. 20, 1998 Sec. 102(e) Date Feb. 20, 1998 PCT Filed Jun. 18, 1997 PCT Pub. No. WO97/48656 PCT Pub. Date Dec. 24, 1997A concrete admixture is provided, which is effective in imparting fluidity to a hydraulic composition such as cement paste, mortar or concrete, particularly in maintaining the fluidity of the composition and which hardly retards the hardening property of the composition. The concrete admixture comprises a copolymer comprising, as structural units, units derived from an ethylenically unsaturated monomer (a) having 25 to 300 moles of C2-C3 oxyalkylene groups per mole of copolymer and units derived from a monomer (b) of an alkyl, alkenyl or hydroxyalkyl ester of an ethylenically unsaturated mono- or di-carboxylic acid. |
