粉煤灰对脱硫石膏-矿渣-粉煤灰复合胶凝材料力学性能的影响

通过研究粉煤灰自身在硫酸盐和石灰双重激发下产生的活性、粉煤灰的碱性以及颗粒Zeta（电位）等,分析不同粉煤灰对脱硫石膏-矿渣-粉煤灰复合胶凝材料力学性能的影响。结果表明,粉煤灰的种类对复合胶凝材料的力学性能影响很大,粉煤灰本身活性的差异不是造成这种影响的主要原因,其主要原因是粉煤灰对矿渣粉的激发程度。粉煤灰的碱性对矿渣粉的激发影响很大,对于普通含钙粉煤灰,碱性越强,激发越好,复合胶凝材料力学性能越好。矿渣粉颗粒的Zeta电位为负,因此粉煤灰颗粒表面的正电荷密度过高,不利于矿渣粉活性的激发。

Influence of Fly Ash on Strength of FGD Gypsum-Slag-Fly Ash Composite Binder

The activity, alkalinity and Zeta potential of fly ash activated by sulfate and lime are studied to analyze the influence of different type of fly ashes on the strength of FGD gypsum-slag-fly ash composite binder in this paper. The result shows that the strength difference of composites prepared by different type of fly ashes is obvious. The main reason of strength difference is not caused by the activity of fly ash but that of slag powder activated by fly ash. And the alkalinity of fly ash has dramatic effect on the strength. The alkalinity of fly ash less than 10% CaO in its chemical compositions is stronger, the level of hydraulicity is higher. The Zeta potential of particles of slag is negative. Therefore, it is detrimental for the hydraulicity of slag when the surface positive charge density of particles of fly ash is high.