| 摘要 |
PROBLEM TO BE SOLVED: To provide a cement admixture mainly used in civil engineering/construction industries, which imparts an excellent expansion performance compared to conventional expanding materials and exerts effects such as inhibition of heat of hydration without delay and inhibition of strength deterioration, and a cement composition. SOLUTION: The cement admixture contains an expandable substance containing free lime, calcium aluminoferrite, hauyne and anhydrite and cationic starch having an initial gelatinization temperature of 35-60°C, a viscosity of 25% aqueous solution at 50°C of 20-3,000 mPa×s and an amount of cationic nitrogen based on the amount of dry starch of 0.2-1.2%. Here, the cationic starch accounts for 0.5-15 pts. of 100 pts. cement admixture. The cement composition contains cement and the cement admixture. COPYRIGHT: (C)2004,JPO&NCIPI |
