Na_2SO_4激发粉煤灰火山灰活性研究

Study on the Pozzolanic Activity of Fly Ash Activated by Na_2SO_4

通过比较抗压强度研究了不同龄期下Na2SO4掺量对粉煤灰-水泥胶凝材料强度的影响,利用X射线衍射(XRD)、扫描电镜(SEM)及能谱仪(EDS)分别分析了粉煤灰-水泥胶凝材料的成分、微观形貌及水化产物的元素组成。结果表明:掺加Na2SO4可显著提高粉煤灰-水泥胶凝材料的强度,随着龄期的延长,材料强度增加;相同龄期下,随着Na2SO4掺量的增加粉煤灰-水泥胶凝材料的强度呈正相关趋势变化,当掺量为3%(质量分数)时,其28d抗压强度提高了82.4%;掺Na2SO4的粉煤灰-水泥胶凝材料水化产物更为丰富,粉煤灰颗粒界面不再清晰可辨,白色针棒状水化产物生长状况良好。

The compressive strength of fly ash-cement cementitious materials （FACM） at different curing age was studied by the method of comparing the compressive strength. The hydration products composition, the micro- structure and element composition of FACM were characterized by X-ray diffraction, scanning electron microscope and energy dispersive spectrometer. The results show that the compression strength of FACM was significantly enhanced by adding Na2SO4 ; this trend was also applied to the increase of curing age. At the same curing age, with the increase of Naz SO4 contents, the compressive strength of FACM was also enhanced, when added with 3%, its compressive strength at 28 d increased 82.4 %. The hydration products of FACM added Naz SO~ were more abundant, the interface of fly ash particles was no longer clear, and white needle stick hydration products grew well.