| 摘要 |
<p>A cement additive composition for concrete surface discoloration prevention which comprises a combination of a cement additive (a) and a water reducing agent (b) in an (a)/(b) ratio of (5-99.5)/(95-0.5) by weight and in which the additive (a) comprises a mixture of compounds represented by the following general formula (1): R1O(AO)n1H which comprise compounds wherein n1 is each of the integers of from 2 to 6 in a total amount of 40 wt.% or more based on the additive (a), the average of n1 is 1.5 to 10, and the additive (a) has a molecular weight distribution, Mw/Mn, of 1.05 or higher and a Z-average molecular weight, Mz, of 200 or higher. It is effective in preventing the surface of a concrete from discoloring. (In the formula, R1 is C1-6 alkyl; A is ethylene and/or propylene; and n1 is a number of 1 or larger.)</p> |
