| 摘要 |
PROBLEM TO BE SOLVED: To obtain an accelerator which gives no undesirable influence on the working environment and the surrounding environment because it contains only a small amt. of alkali metal component and which shows excellent accelerating characteristics and strength developing property by incorporating a calcium aluminate glass(CA glass), aluminum sulfate and gypsum. SOLUTION: The CA glass is usually prepared by mixing a calcia source material, alumina source material and silica source material, heating the mixture in an electric furnace or the like at a high temp. as 1200 to 1700 deg.C to produce a molten calcium alumino mineral expressed by 3CaO.Al2 O3 , 12CaO.7Al2 O3 , CaO.Al2 O3 or the like, and rapidly cooling it to vitrify. The CA glass preferably contains 35 to 55 wt.% CaO. It is sufficient that the vitrification degree is >=60%. To 100 pts.wt. of the CA glass, 10 to 30 pts.wt. of aluminum sulfate and 10 to 150 pts.wt. of gypsum calculated both as anhydrides are preferably mixed. The grain size of the accelerator is usually controlled to 3000 to 9000 cm<2> /g Brane value. |
