CEMENT ADMIXTURE WHICH GIVES LOW LOAD ON ENVIRONMENT AND CEMENT COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a cement admixture which gives low load on the environment and a cement composition from which concrete having high strength and a small discharge amount of carbon dioxide can be obtained. SOLUTION: The cement admixture which gives low load on the environment contains gypsum anhydride produced as an industrial byproduct having <=pH 4.5, and it discharges carbon by <=0.02 kgC/m3 calculated as the carbon element. Preferably, the average particle size of the gypsum anhydride is <=10μm, and the admixture contains silica fine powder produced as an industrial byproduct. The cement composition contains a cement and the cement admixture which gives low load on the environment.