| 摘要 |
PROBLEM TO BE SOLVED: To provide a cement additive reducing the shrinkage of concrete even when the quantity of an expanding material or a shrinkage reducing agent to be added is small, and to provide a cement composition. SOLUTION: The additive contains (A) one or more kinds of mineral powder selected from siliceous shale powder and diatom earth powder in a hydrated state and (B) an expanding material and/or a shrinkage reducing agent, and the water content in the mineral powder is 5-40 mass%. The cement composition includes cement and the cement additive. The average particle diameter of the mineral powder is preferably 0.5-30μm. COPYRIGHT: (C)2010,JPO&INPIT |
