上海地区不同商品粉煤灰的化学活性

Chemical Activity of Various Commercial Fly Ashes in Shanghai Area

对上海地区多种商品粉煤灰的化学活性作了研究与比较。测试结果表明 ,常温下不同灰样在FA Ca(OH) 2 H2 O系统中的反应率有一定差别 ,随龄期延长 ,差别逐渐减小 ,在 180天差值不超过 3 5 %。Ⅱ级磨细灰的化学活性优于Ⅱ级分选灰和Ⅰ级分选灰。但在高温 (80℃ )下 ,分选灰的反应速率常数大于磨细灰。酸溶法不适用于高钙灰反应率的测定。强度测试表明商品高钙灰的活性不低于低钙灰 ,Ⅰ级混烧高钙灰活性最高。

In this paper, the chemical activity of commercial fly ashes with different type taking from Shanghai area are researched and compared. The test results show that, in normal temperature condition, the reaction ratio in FA Ca(OH) 2 H 2O system are different between various samples, but this differences progressively reduced with a prolongation of age. At 180 days of age, the value of difference is not more than 355. The grade Ⅱlow Calcium grinding fly ashes is better than that of grade Ⅱ and grade Ⅰ separate collected fly ashes. But at more high temperature (80℃) , the reaction velocity coefficient of separate collected fly ashes is higher than grinding fly ashes. Measuring reaction ratio by means of acid dissolved method is not compatible for high Calcium fly ashes. The results of strength test show that the activity of commercial high Calcium fly ashes are not lower than that of low Calcium fly ashes. The activity of grade Ⅰ high Calcium fly ashes are best of all samples.