| 摘要 |
<p>PURPOSE:To offer the fly ash in which properties are easily improved and giving low heating and high durability cement by subjecting fly ash to heat treatment at a regulated temp. for a regulated time and thereafter cooling it under specified cooling conditions. CONSTITUTION:Fly ash, i.e., vitrified coal ash is subjected to heat treatment at 300 to 900 deg.C for 30 sec to 30 min. Next, the fly ash is cooled to 150 deg.C at the cooling rate of >=20 deg.C/min. In this way, the properties of the fly ash can be activated, and the cement incorporated with the heat-treated fly ash has low calorific value. The concrete by using the above cement has high long-period age strength and less drying shrinkage, which is then suitably used for mass concrete, watertight concrete, etc.</p> |
