| 摘要 |
PROBLEM TO BE SOLVED: To provide a powdery additive for a cement composition, in which a powdery material and a surfactant are hardly separated. SOLUTION: The powdery additive for the cement composition is constituted of shirasu balloons (S) and a surfactant (K). A preferable surfactant is a shrinkage-reducing agent and a more preferable surfactant is a shrinkage-reducing agent containing an oxyalkylene compound expressed by general formula (1). Further, the surfactant may contain an oil-absorbing powdery material. In the formula, R is a hydrogen atom, a 1-7C alkyl group or 5-6C cycloalkyl group; A is a 2-3C alkylene group; O is an oxygen atom, H is the hydrogen atom and n is an integer of 1-10. COPYRIGHT: (C)2005,JPO&NCIPI |
