大掺量粉煤灰混凝土早期抗压强度变化规律

Variation Law of Early Compressive Strength of Concrete with Large Amount of Fly Ash

粉煤灰是燃煤电厂排放的废弃物,不仅可等量替代混凝土中部分水泥用量,改善混凝土的工作性能,有助于低碳环保,而且延缓水泥水化速度。因此,合理的粉煤灰用量可获得良好的效益,但粉煤灰等量替代水泥的比例会影响自密实混凝土的性能。通过粉煤灰掺量为50%、70%两组混凝土试件在养护时间分别为3、7和14 d的早期强度的试验研究(抗压强度和无损检测回弹值),对所得试验数据进行分析,探讨饱和大掺量粉煤灰混凝土的早期强度。试验结果表明,饱和大掺量粉煤灰混凝土早期强度随粉煤灰掺量增大而降低。研究结论对于类似理论研究和工程实践都具有参考意义。

Fly ash is the waste discharged by coal-fired power plants,not only can replace part of the cement dosage in the concrete in equal amounts,improve the working performance of concrete,help low-carbon environmental protection,and delay the speed of cement hydration.Therefore,the reasonable amount of fly ash to obtain good benefits,but the proportion of fly ash instead of cement will affect the performance of self-compacting concrete.In this paper,the experimental study of the early strength of two groups of concrete specimens with fly ash doping of 50%and 70%in the maintenance time of 3、7 and 14d respectively(compressive strength and nondestructive testing rebound value)was studied.The experimental data were analyzed to explore the early strength of saturated fly ash concrete.It is concluded that the early strength of saturated fly ash concrete decreases with the increase of fly ash doping.Its conclusions are of reference significance for similar theoretical research and engineering practice.