| 摘要 |
PROBLEM TO BE SOLVED: To provide a powder accelerator hardly proceeding aeration, capable of stably exhibiting high accelerating property, hardly generating material separation or flow variation during force feeding the accelerator, and having no trouble on force feeding property.SOLUTION: There is provided a powder accelerator containing alkali metal carbonate and alkali metal aluminate, and calcium aluminate as an active ingredient, and consisting of 30 to 70 pts.mass of a 10 μm or more coarse grain having an average moisture content of 0.2 mass% or more and less than 1.0 mass% and 70 to 30 pts.mass of less than 10 μm coarse grain having the average moisture content of 0.2 mass% or less. |
