| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cement composition capable of obtaining a hardened body excellent in dimensional stability and durability and having proper hardening rate by adding a powder obtained by applying a specific amount of mechanical energy to aluminum hydroxide, calcium hydroxide and an oxy carboxylic acid (salt) to cement. SOLUTION: The powder obtained by applying 0.5-30 kwh/kg, preferably 1.0-10 kwh/kg mechanical energy to the aluminum hydroxide desirably having 0.1-500μm, further desirably 0.1-100μm average particle diameter by a ball mill, the calcium hydroxide having 0.1-100μm average particle diameter and the oxy carboxylic acid (salt) (e.g. sodium citrate) are added to the cement. The quantity of the powder and the calcium hydroxide to be added to 100 pts.wt. cement is desirably 1-100 pts.wt. in the molar ratio Al/Ca of 0.5-5.0 and the quantity of the oxy carboxylic acid (salt) to the same is desirably 0.1-3 pts.wt. |
