| 摘要 |
PROBLEM TO BE SOLVED: To provide a cement admixing agent having excellent expansion characteristics and a cement composition containing the same. SOLUTION: The cement admixing agent contains free lime obtained by heat treating a raw material composed of CaO, Al2O3 and Fe2O3, clinker containing C3A and calcium alumino-ferrite and gypsums. The cement admixing agent is characterized in that calcium silicate is contained in such a manner that the silica modulus is in the range of <1.0, the free lime is contained in an amount of 30 to 60%, and one of the gypsums is an anhydrous gypsum. Further, the cement composition contains cement and the cement admixing agent. |
