| abstract |
PROBLEM TO BE SOLVED: To provide a cement admixture and a cement composition mainly used in the civil engineering and construction industry, which have an excellent rust prevention effect, a shielding effect of chloride ions entering from the outside, and exhibit an effect of suppressing Ca leaching. provide. A cement admixture containing a calcium aluminate compound having a CaO / Al 2 O 3 molar ratio of 0.15 to 0.7 and nitrite, and a calcium aluminate compound having a CaO / Al 2 O 3 molar ratio of 0.15 to 0.7. The cement admixture having a fineness of 2,000 to 6,000 cm 2 / g in terms of Blaine specific surface area, the cement admixture wherein nitrite is lithium nitrite and / or calcium nitrite, aluminum hydroxide and nitrite Cement admixture in which the blending ratio of Al 2 O 3 / NO 2 is 1/4 to 4/1, and cement, calcium aluminate having a CaO / Al 2 O 3 molar ratio of 0.15 to 0.7 A cement composition containing a compound and nitrite is used as a constituent. [Selection figure] None |