| 摘要: |
| 通过X射线衍射（XRD）、扫描电镜（SEM）、热重差示扫描量热分析（TG DSC）和高压压榨法（PWE），研究了不同磷石膏掺量的微膨胀道路基层水泥中水化产物与孔隙液主要元素浓度的演化.结果表明：在水化3d时，硬化水泥浆体中钙矾石的生成量随着磷石膏掺量的增加先增大后减小；水化28d后钙矾石的生成量随着磷石膏掺量的增加而增加；磷石膏溶解生成的SO2-4对粉煤灰活性有很好的激发作用，粉煤灰中的Al相在水化7d后开始大量溶出，孔溶液中Al、Ca和S元素浓度的变化能很好地反映水泥的水化进程；不同磷石膏掺量下各龄期水泥的孔隙液pH值均在1255上下波动；水化60d时硬化水泥浆体均比较密实，磷石膏掺量较大的水泥在水化产物表面仍有大量钙矾石生成，孔隙中有更多的针棒状钙矾石存在. |
| 关键词: 磷石膏 孔隙液 微膨胀水泥 水化产物 钙矾石 |
| DOI：103969/j.issn.1007 9629202006003 |
| 分类号: |
| 基金项目:“十三五”国家重点研发计划项目（2016YFB0303603）；国家重点基础研究发展计划(2015CB655100) |
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| Effect of Phosphogypsum on Pore Solution and Hydration Products of Slight Expansive Cement |
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ZHAO Deqiang1, ZHANG Bingliu1, SHEN Weiguo1, LI Wenwei2, HUO Xujia2
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1.School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China;2.China Three Gorges Corporation, Beijing 100038, China
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| Abstract: |
| X ray diffraction(XRD), scanning electron microscopy(SEM), thermogravimetric differential scanning calorimetry(TG DSC) and pore water expression(PWE) were used to investigate the hydration products and pore solution element concentration with different content of phosphogypsum in slight expansive road base cement. The results show that the amount of ettringite increases at first and then decreases in hardened cement paste with the increase of phosphogypsum content at 3d while it increases gradually with the increase of phosphogypsum at 28d. Sulfate generated by the dissolution of phosphogypsum has a good stimulation effect on the activity of fly ash. Al phase begins to dissolve largely after hydration for 7d. The concentration changes of Al, Ca and S in pore solution can reflect the hydration process of cement. The pH value of cement fluctuates slightly at 1255 with different phosphogypsum contents at different ages. After 60days of hydration, the hardened cement paste are denser and a large amount of ettringite still exists on the surface of the cement hydration products that contain a large amount of phosphogypsum, and there is more amount of needle like ettringite in the pores. |
| Key words: phosphogypsum pore solution slight expansive cement hydration product ettringite |
