| 摘要 |
PROBLEM TO BE SOLVED: To provide a cement admixture and a cement composition which impart excellent antirust effects to inner reinforcing bars, have shielding effects against chloride ion permeation intruding from outside, and further can inhibit pore formation because of little leaching of Ca ion, in a cement concrete hardened body.SOLUTION: A cement admixture contains a calcium ferroaluminate compound with a CaO/AlOmole ratio of 0.15-0.7 and an FeOcontent of 0.5-20 mass%, and the content of a calcium ferroaluminate microparticle having ≤10 μm size is ≤15 mass%. It is preferable that Blaine specific surface area is 2,000-7,000 cm/g. A cement composition includes cement and the cement admixture. |
