硅酸盐学报

水对碱矿渣胶凝材料介电性能的影响(Ⅰ)

作者：崔学民邱树恒曹德光周济

单位：广西大学化学化工学院广西大学化学化工学院广西大学化学化工学院清华大学新型陶瓷与精细工艺国家重点实验室南宁530004 南宁530004 南宁530004 北京100084

关键词：水胶凝材料介电常数介电损耗吸附

分类号：O611.3

出版年,卷(期):页码：2007,35(6):791-795

DOI：

摘要：

研究了碱激发矿渣(alkali active slag cement,AASC)胶凝材料的介电性能。结果表明:在100℃干燥4h可以消除胶凝材料硬化浆体中自由水对其介电性能的影响。介电频谱表明:在高频区域,胶凝材料的介电常数(εr)在6～8之间,介电损耗(tanδ)在0.02～0.04之间;但是,干燥样品放置在相对湿度约为40%的大气环境中与水汽接触时,胶凝材料表面的毛细孔吸附空气中的水汽,饱和吸附量的质量分数(下同)约为1.2%,导致胶凝硬化浆体的εr和tanδ急剧增大。因此,通过低温干燥处理不能改善胶凝硬化浆体的吸水性能。进一步的差热分析(differential thermal analysis,DTA)和热重分析(thermogravimetry analysis,TGA)可知:100℃干燥样品中仍有2%左右的化合水,这是干燥样品tanδ仍然高于陶瓷材料的主要原因。

Dielectric performances of hardening alkali active slag cement(AASC)paste were studied.The experimental results show the drying method(100℃for 4 h)that could depress the effect of free-water on the dielectric performances of the AASC.The dielec-tric frequency also shows the dielectric constant(εr)is 6—8 and the dielectric loss(tanδ)is 0.02—0.04 at high frequency.With the increase of deposition time in air with a relative humidity of about 40%,the AASC would absorb the water vapor in the air.The satu-rated absorption is about 1.2%in mass(the same below),so theεr and tanδincreased rapidly.Therefore,the low temperature drying method could not completely eliminate the absorption of the AASC paste.In addition,the dried AASC paste still contained about 2% hydrate water of hydration that was proved by the differential thermal analysis and thermogravimetry analysis,so,the tanδof the AASC paste was higher than ceramic material.

基金项目：

国家自然基金(50602006)资助项目

作者简介：

参考文献：

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