摘要
在适当煅烧温度下,分别运用Na2CO3、CaO和CaF2等材料对二级低钙粉煤灰进行了改性研究,从而促进了粉煤灰活性的发挥.运用XRD、TGA等测试方法,研究了热处理粉煤灰的晶相组成及其水化特性.研究表明,粉煤灰能够和这些组分发生化应,形成NaAlSiO4、CaO·Al2O3·SiO2、α-Ca2SiO4和Na,Ca)(SiAl4)4O8等晶相,玻璃态网络结构也发生了相应的变化.热处理粉煤灰表现出了良好的胶凝性能.上述3种组分对粉煤灰活性的影响不尽相同,其中CaF2对粉煤灰的活性有更加积极的影响.
The original fly ash containing the chemical agent,such as Na 2 CO 3 ,CaO and CaF2,was treated at the temperature950°C,after that and the cementitious properties of fly ash was significantly improved.The phase composition of the heat-treated fly ash and its hydrated samples were examined with XRD and TGA.The results show that Na 2 CO 3 ,CaO and CaF 2 could change the phase composition of the fly ash and the new crystaline phases NaAlSiO 4 and(Na,Ca )(SiAl ) 4 O 8 will exist in the heat-treated samples.The heat-treated fly ash shows good cementitious properties.The test results of TGA for the heat-treated fly ash show that the gel content of the fly ash containing0.4wt%CaF 2 hydrated for2months is the highest com-pared with others.CaF 2 has the best effect on the cementitious property of fly ash among the three chemical agents CaF 2 ,Na 2 CO 3 and CaO.From the XRD results of the heat-treated samples hydrated for2months,it is concluded that the CaF 2 mainly changes the glass structure of fly ash and the improvement of the ce-mentitious properties of fly ash results from the changes of glass structure.
出处
《材料科学与工艺》
EI
CAS
CSCD
2002年第1期73-76,共4页
Materials Science and Technology
基金
中国建筑材料科学研究院科研基金资助项目(YA-14)
