| 摘要 |
PROBLEM TO BE SOLVED: To obtain an active powder having an optimally regulated solubility of calcium ion and aluminum ion in water, a rapid hardening rate, and improved durability and dimensional stability by making the cement composition include an aluminum compound powder, a water-soluble calcium compound powder and a chloride powder. SOLUTION: This active powder is obtained by blending (A) an aluminum compound powder having 2-100 cal/g-powder calorific value when dipping the active powder in water at a normal temperature, or having >=150, preferably 300-3,000 ppm/g - powder dissolved amount of aluminum when dipping the active powder in an aqueous solution of an alkali having pH 12.5, with (B) a water-soluble calcium compound powder having 0.1-500μm average particle diameter, and (C) a chloride powder having 0.1-100μm average particle diameter, regulated so that the ratio of the number of Ca atoms in the component B to the number of Al atoms in the component A may be 0.1-10, preferably 0.5-2, and the ratio of the number of Cl atoms in the component C to the number of the Al atoms in the component A may be 0.1-5, preferably 0.2-2. |
