湿排粉煤灰活性影响因素试验

Factors influencing activation of wet fly ash

选用4种低钙粉煤灰,通过实验室模拟方法制备湿排粉煤灰,采用抗压强度比表示粉煤灰活性,研究了模拟湿排时间、温度、pH值以及海水湿排的粉煤灰活性变化。结果显示,随着湿排时间延长,粉煤灰活性呈早期降低快后期渐缓趋势;高温湿排的早期粉煤灰活性有一定提高;酸性环境能明显提高粉煤灰活性;海水湿排粉煤灰活性变化规律与淡水湿排粉煤灰类似。可以认为,湿排粉煤灰活性总体呈降低趋势,有些情况下湿排粉煤灰活性表现增加,是因为湿排溶蚀后暴露出更多的活性物质有利于粉煤灰活性的发挥。

To use fly ash, it is necessary to understand its activity variation under different wet conditions. Four low-calcium wet fly ash preparations are simulated in the laboratory. Fly ash activity is indicated by measuring specific compressive strength. The variation of fly ash activity at,a range of wet periods, temperatures and wetting solution pH values is investigated. Sea water and tap water as wet solutions are compared. It is shown that of fly ash activity deceased as wet time increased, dropping quickly early on and slowing down over a long period. Enhanced early fly ash activity can be obtained in a high temperature wet condition. The activity improvement is more obvious in acidic solutions. The activity variation of wet fly ash in sea water is quite similar to that in tap water. The overall activity of wet fly ash decreased as the wet time is extended, while some exceptions occur due to a higher percentage of active parts after wetting.