活性MgO碱性激发粒化高炉矿渣固化黏土的抗硫酸盐侵蚀试验研究

发布时间：2018-07-03 01:46

本文选题：活性氧化镁 + 粒化高炉矿渣粉　；参考：《岩土力学》2015年S2期

【摘要】：通过系列室内试验,研究了硫酸盐长期浸泡环境下GGBS-Mg O固化黏土的物理和力学性质及微观特征变化规律,并与水泥固化黏土进行对比,揭示了GGBS-Mg O固化黏土抵抗硫酸盐侵蚀的机制。与水泥固化黏土相比,硫酸盐浸泡条件下GGBS-Mg O固化黏土表面完整度较好;质量变化率在浸泡120 d时仅为水泥固化黏土的0.25倍;固化黏土体p H略小于同期水泥固化黏土;浸泡初期GGBS-Mg O固化黏土强度增长达20%,同周期时无侧限抗压强度较水泥固化黏土高15%~80%。X射线衍射试验(XRD)表明,硫酸盐侵蚀下GGBS-Mg O固化黏土中水化硅酸钙(C-S-H凝胶)的峰值高于水泥固化黏土,而钙矾石(AFt)的XRD图谱峰值明显低于水泥固化黏土。电镜扫描试验结果表明,两种固化黏土中钙矾石形态明显不同:钙矾石在水泥固化黏土中以团聚型晶体存在,可具较强膨胀性,而在GGBS-Mg O固化黏土中则以细短形态分布于颗粒间,可有效填充试样孔隙,使其具备良好的抗硫酸盐侵蚀能力。
[Abstract]:Through a series of laboratory tests, the physical and mechanical properties and microcosmic characteristics of GGBS-MgO solidified clay under the condition of sulphate soaking for a long time were studied and compared with that of cement solidified clay. The mechanism of resistance of GGBS-Mg O solidified clay to sulfate erosion was revealed. Compared with cement cured clay, the surface integrity of GGBS-Mg O solidified clay is better than that of cement solidified clay, the mass change rate is only 0.25 times that of cement solidified clay after 120 days of soaking, the pH of solidified clay is slightly lower than that of cement solidified clay at the same time. At the beginning of soaking, the strength of GGBS-Mg O solidified clay increased to 20, and the compressive strength of unconfined clay in the same period was 15% higher than that of cement solidified clay. The results of X-ray diffraction (XRD) showed that the strength of GGBS-MgO solidified clay increased to 20%. The peak value of calcium silicate hydrate (C-S-H gel) in GGBS-Mg O cured clay is higher than that in cement cured clay under sulfate erosion, while the peak value of XRD of ettringite (aft) is obviously lower than that of cement cured clay. The SEM results show that the morphology of ettringite in two kinds of solidified clay is obviously different: ettringite in cement solidified clay exists as agglomerated crystal and can expand strongly. In the GGBS-MgO solidified clay, the particles are distributed in a short form, which can effectively fill the pore of the sample and make it have a good resistance to sulfate erosion.
【作者单位】：东南大学岩土工程研究所;
【基金】：国家自然科学基金重点项目(No.41330641) 国家自然科学基金(No.51278100,No.41472258) 江苏省自然科学基金杰出青年项目(No.BK2012022) 江苏省自然科学基金(No.2011618)
【分类号】：TU521;TU411

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