| 摘要 |
PROBLEM TO BE SOLVED: To provide means for further improving the performance (slump retention capability and compression strength, in particular) of cement admixture.SOLUTION: A cement admixture is made from a copolymer with a component ratio of Xwt.% of a first polyalkylene glycol di(meth)acrylate (a) represented by the general formula (1) in the specification, Xwt.% of a first polyalkylene glycol (meth)acrylate (b) represented by the general formula (2), Ywt.% of a second polyalkylene glycol di(meth)acrylate (c) represented by the general formula (3), Ywt.% of a second polyalkylene glycol (meth)acrylate (d) represented by the general formula (4), Zwt.% of carboxylic acid-based monomer (e) represented by the general formula (5), and Zwt.% of other monomer (f) copolymerizable with the (a) to (e), or from a salt of the copolymer neutralized with an alkaline material. When X+Y+Z+Z=100 is assumed, then X:Y:Z:Z=5 to 70:10 to 90:5 to 40:0 to 50, and X+Y=60 to 95 are satisfied. When X+X+Y+Y=100 is assumed, then X+Y=0.1 to 10 is satisfied. |
