| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a cement composition that suppresses drastic decrease in fluidity occurring immediately after kneaded and that develops high strength.SOLUTION: The cement composition comprises a cement clinker and gypsum, in which the cement clinker comprises 50 to 60 mass% of 2CaO-SiOand 1.3 to 4 mass% of 3CaO-AlOwith respect to the mass of the cement composition. The cement composition further contains tin or a tin compound by 40 to 250 mg in terms of tin with respect to 1 kg of the cement clinker. The percentage of the gypsum is 0.5 to 2.2 mass% in terms of SOwith respect to the mass of the cement composition. The cement composition has a Blaine specific surface area of 3000 to 4000 cm/g. The gypsum contains hemihydrate gypsum; and the hemihydrate gypsum shows an intensity ratio of 65 to 115 of the X-ray diffraction intensity on a 114-plane to the X-ray diffraction intensity on a 220-plane.</p> |
