| 摘要 |
<p>To provide a high strength cement admixture which allows concrete to achieve steam-curing at an earlier stage because such concrete attains great initial strength development without retardation of setting even with use of a large amount of a high performance water reducing agent, and a process for producing a concrete product. A high strength cement admixture characterized by comprising a ground mixture of gypsum having a particle size of from 2,500 to 9,000 cm 2 /g as a Blaine specific surface area and glycerin, and preferably a silica material having a particle size of at least 5,000 cm 2 /g as a Blaine specific surface area and containing at least 60 mass% of SiO 2 , wherein the content of the glycerin is from 0.1 to 10 parts by mass per 100 parts by mass in total of the gypsum and the glycerin, and the content of the silica material is from 45 to 90 parts by mass, per 100 parts by mass in total of the gypsum, the silica material and the glycerin; and a process for producing a concrete product, characterized by blending the above high strength cement admixture, with cement, in an amount of from 2 to 15 parts by mass per 100 parts by mass in total of the cement and the high strength cement admixture.</p> |
