| 摘要: |
| 应用X射线衍射分析、差热热重分析、扫描电子显微镜能量色散仪观察分析等手段，研究转炉钢渣中MgO，f CaO相和RO相的微观结构特征、水化特点和膨胀规律.结果表明：转炉钢渣中MgO与FeO，MnO形成MgO基连续固溶体RO相，化学式为MgO·1.20FeO·0.05MnO·0.03CaO，压蒸条件下稳定.MgO固溶FeO和MnO会使其水化活性下降，当FeO/MgO摩尔比和MnO/MgO摩尔比分别为1︰1和0.5︰1时，RO相是稳定相.钢渣对水泥安定性的不良影响是由其f CaO相水化反应造成的.钢渣中f CaO相固溶0.15mol FeO，晶粒大，晶胞参数小，分布均匀，标准沸煮法检验只有46.2%（质量分数）水化消解，即使沸煮8h也只有70.8%（质量分数）水化消解.钢渣水泥安定性应采用压蒸法检验.钢渣水泥20℃水养护条件下快速膨胀2个月、慢速膨胀约15个月，膨胀缓和、周期长，有补偿大体积混凝土温度应力的作用. |
| 关键词: 安定性 钢渣水泥 RO相 游离氧化钙 氧化镁 |
| DOI：10.3969/j.issn.1007 9629.2012.05.002 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（50872105）；陕西省重点学科建设专项资金资助项目 |
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| Study on Volume Stability Problems of Cement Caused by Steel Slag |
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HOU Xin kai1, XU De long1, XUE Bo2, LI Hu sen2
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1.School of Materials Science and Engineering, Xian University of Architecture and Technology, Xian 710055, China;2.Shuangliang Cement Limited Company of Shanxi, Taiyuan 030003, China
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| Abstract: |
| Converter steel slag was selected to study micro structural features, hydration characteristics and expansion properties of MgO, f CaO phase and RO phase in the slag using X ray diffraction(XRD), thermogravimetry differential thermal analysis(DTA TG), scanning electron microscope(SEM) and energy dispersive X ray diffraction analysis(EDX). The results show that MgO contained in converter steel slag combines with FeO and MnO to form the RO phase that is a complete MgO FeO MnO solid solution. The chemical formula is MgO·1.20FeO·0.05MnO·0.03CaO, which is stable phase tested by autoclaving. The formation of the solid solution of FeO, MnO and MgO will reduce MgO hydration activity; when the mole ratios of FeO/MgO and MnO/MgO reach to 1︰1 or 0.5︰1, RO phase is indubitable stable. The bad effect of steel slag on cement soundness is caused by hydration reaction of f CaO phase in steel slag. The f CaO phase in steel slag is solid solution containing about 0.15 mol FeO with larger size grain and smaller unit cell parameter, which is evenly distributed. Only 46.2%(by mass) of the f CaO phase in steel slag will hydrate if tested by standard boiling method, and only 70.8%(by mass) will hydrate even if boiled for 8 h. Determination of the soundness of steel slag cement should be in accordance with autoclaving test.The rapid expansion period of the steel slag cement cured in 20℃ water lasts 2 months, while the slow expansion period of that cement lasts 15 months. This long standing expansivity has the effect of compensating thermal stress of mass concrete. |
| Key words: soundness steel slag cement RO phase free lime(f CaO) magnesia(MgO) |
