| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a combination of a cement dispersant and a shrinkage-reducing agent having excellent their compatibility with each other, which enables both effects of a shrinkage reducing property and a water-reducing property to be synergistically improved.SOLUTION: There is provided a concrete admixture that comprises: a polycarboxylic acid-based cement dispersant composed of a polymer compound having a polyamide-polyamine chain; and a shrinkage-reducing agent for a cement composition, comprising compound A represented by formula [1] and compound B represented by formula [2] in a mass ratio of compound A:compound B=99:1 to 50:50. (In formula [1], Rand Reach independently represent a C1-4 alkyl group; and n represents an average number of moles of addition of oxyethylene (EO) groups and is 2 or 3). (In formula [2], Rrepresents a C9-24 hydrocarbon group; and mand meach independently represent an average number of moles of addition of oxyethylene (EO) groups and is 0 to 30, where a total value of mand mis 1 to 30).</p> |
