| 摘要 |
PROBLEM TO BE SOLVED: To provide a cement admixture exhibiting an excellent effect of a stably large expansion amount in an early stage at a normal precuring time, high strength and a good adhesion property, and to provide a cement composition, and to provide concrete using the same. SOLUTION: The cement admixture is a substance obtained through thermal treatment of a CaO material, an Al2 O3 material, a Fe2 O3 material, and a CaSO4 material. The cement admixture is the substance obtained from thermal treatment of expansion substance containing free lime, calcium aluminoferrite and an anhydrous gypsum, and the CaO material, the Al2 O3 material and CaSO4 material. This cement admixture comprises the expansion substance containing the free lime, calcium sulfoaluminate and the anhydrous gypsum. The cement composition comprises cement and the cement admixture. The concrete is the cement composition formulated with aggregate, water, and a chemical admixture. This cement admixture is characterized by being formulated into the cement in a unit amount of 15-100 kg/m<3> . |
