不同激发剂对粉煤灰火山灰活性的影响

Study of Effect of Different Activators on the Pozzolanic Activity of Fly Ash

探讨不同激发剂对粉煤灰不同时期火山灰活性的影响。结果表明:单掺适量的不同激发剂可以不同程度地提高粉煤灰早期、中期与后期的火山灰活性,其中早期的激发作用最大,后期的激发作用最小。且不同时期激发作用效果从大到小的顺序依次为氯化物、硫酸盐、氢氧化物,其中当氯化钠掺量为2%时激发作用效果最大。当水灰比为0.48时激发剂对粉煤灰不同时期火山灰活性的激发效果均优于水灰比为0.46时的激发效果。且当水灰比从0.46增至0.48时,各水泥试样的3 d抗压强度比值增幅最大,28 d抗压强度比值增幅最小。

Effect of different activator on the pozzolanic activity of fly ash in different stage were investigated .The results show that the pozzolanic activity of fly ash at the early stage ,middle stage and later stage can be improved in different extents by adding proper content of different activator to cement. The effect of activator on the early stage is the best and that on the later stage is the worst. The exciting effect order relation from great to small in different stages is chloride, sulfate and hydroxide. The exciting effect of sodium chloride with the content of 2% is the best. When water cement ratio is 0.48, the effect of activator on the pozzolanic activity of fly ash in different stage is better than that when water cement ratio is 0.46. The increasing rate of compression strength ratio at 3 d of each cement sample is the fast, but the increasing rate of compression strength ratio at 28 d of each cement sample is the slowest with water cement ratio from 0.46 to 0.48.