粉煤灰对煤矸石混凝土界面过渡区的改性效应

Modification Effect of Fly Ash on Interfacial Transition Zone of Coal Gangue Concrete

为了促进煤矸石在混凝土生产中的使用,考虑不同粉煤灰掺量(0%、10%、20%、30%、40%)对煤矸石混凝土(Coal gangue concrete,CGC)界面过渡区(Interfacial transition zone,ITZ)结构的影响,从宏观力学和微观力学两个尺度出发,揭示了粉煤灰对CGC的ITZ微观结构及宏观性能的改性机理。研究表明:在宏观力学上,掺加30%的粉煤灰可以提高CGC的劈裂抗拉强度。在微观力学上,加入30%的粉煤灰能显著提高ITZ的薄弱区的硬度值,使其硬度值的分布变得较为均匀。掺加粉煤灰后CGC的ITZ厚度明显减小。这说明掺入的适量粉煤灰在CGC的ITZ上发挥了物理作用及化学作用,改变了CGC的ITZ结构。

In order to promote the use of coal gangue in the concrete production,the influence of different fly ash content(0%,10%,20%,30%,40%)on the structure of interfacial transition zone(ITZ)of coal gangue concrete(CGC),from two dimensions of macromechanics and micromechanics,revealed the modification mechanism of fly ash on microstructure and macroscopic properties of ITZ of CGC.Research shows that:in macroscopic mechanics,the splitting tensile strength of CGC could be improved by adding 30%fly ash.In micromechanics,30%fly ash could significantly improve the hardness value of weak zone of ITZ,and made the hardness value became more uniform.When fly ash was added,the thickness of ITZ decreased obviously.This indicated that the appropriate fly ash has played a physicochemical role in the ITZ of CGC and changed the structure of ITZ.