Na2S04激发粉煤灰火山灰活性研究.pdf

Na2SO4激发粉煤灰火山灰活性研究/郵轶兵等
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Na2SO4激发粉煤灰火山灰活性硏究
轶兵,王庆平
(安徽理工大学材料科学与工程学院,准南232001)
摘要通过比较抗压强度研究了不同龄期下Na2SO2掺量对粉煤灰一水泥胶凝材料强度的影响,利用X射线
衍射(XKRD)、担描电镜(SEMの及能谱仪(EDS)分別分析了粉煤灰-水泥胶凝材料的成分、微观形貌及水化产物的元亲
组成。结果表明:掺加Na2SO4可显著提高粉煤灰一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
随着Na2SO,掺量的增加粉煤灰一水泥胶凝材料的强度呈正相关趋势变化,当摻量为3%(质量分数)时,其28d抗
压强度提高了82.4%;掺Na2SO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。
关键词硫酸钠粉煤灰火山灰活性激发剂
中图分类号:TQ172
文献标识码:A
Study on the Pozzolanic Activity of Fly Ash Activated by Na2s04
QIU Yibing, WANG Qingping
( School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan 23001)
Abstract 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 FM 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 Na2 SO,; this trend was also applied to the increase of curing age. At the same curing age, with the increase
of Na SO contents, the compressive strength of F ACM was also enhanced, when added with 3%, its compressive
strength at 28 d increased 82. 4%. The hydration products of FACM added Na SO were more abundant, the interface
of fly ash particles was no longer clear, and white needle stick hydration products grew well.
Key words sodium sulfate, fly ash, pozzolanic activity, activator
实验
我国是燃煤发电的大国,毎年由此产生的粉煤灰达上亿1.1原材料
吨,粉煤灰的综合利用和开发对环保、节能、资源利用具有十
所用粉煤灰为淮南平圩电厂三级粉煤灰,其主要矿物组
分重要的意义1:2。粉煤灰作为胶凝材料尽可能多地替代混成为石英、莫来石和氧化钙(见图1)。
凝土或砂浆中的水泥,充分发挥其火山灰活性及其他有益效
应,具有重要的社会意义和经济意义-5。相关研究及应用
Q-石英
表明,粉煤灰替代水泥量达到一定程度后会显著降低浆体的
100
M-莫来石
C-氧化钙
早期强度,极大地限制了粉煤灰的应用-。因此,对大掺量
粉煤灰-水泥胶凝材料早期火山灰效应的激发研究是当前研
究的重点问题。常用的化学激发方式有碱激发、氯盐激发和
M
硫酸盐激发?。考虑到强碱易引起碱集料反应,氯盐易对钢
筋造成锈蚀,本实验拟采用硫酸盐类激发剂NaSO)对粉煤
Q CM C
CM M
灰火山灰活性进行激发试验,通过比较抗压强度考察不同龄
102030
0607080
期下Na2SO掺量对粉煤灰-水泥胶凝材料强度的影响,用
XRD分析其水化产物组成,用SEM及EDS观察其微观形貌
图1粉煤灰的XRD图
和区域元素组成,并对其激发机理进行简要分析。
Fig. I XRD pattern of fly ash
关安徽省自然基金(1208085QE100);安傲省救育斤自然基金重大项目(KJ2012ZD5);安徽理工大学博士基金项目
邱轶兵:男,1972年生,硕士,研究方向为无机非金属材料E-mail:qybwxi@126.com