侵蚀条件下粘土水泥结石的劣化试验研究

发布时间：2018-04-14 01:17

本文选题：粘土水泥浆材 + 防渗注浆　；参考：《长沙理工大学》2015年硕士论文

【摘要】：粘土水泥浆材属于无机类灌浆材料,具有良好的稳定性、抗冲性、环境友好且大量节约水泥用量,是理想的防渗注浆材料,被广泛的应用到各领域的防渗注浆工程。经工程验证,其防渗堵漏的效果能满足施工的要求,然而结石体的抗侵蚀性能决定了其在软水及其他侵蚀溶液长期作用下的使用效果及耐久性,地下工程施工位置隐蔽且多属于永久性工程,使用年限长,浆材抗侵蚀性能的研究具有重要意义。本文分析了粘土水泥浆材的劣化机理并结合粘土水泥浆材的抗软水侵蚀试验和抗硫酸盐侵蚀试验,以宏观(CaO的累积溶出率、质量损失率、强度)和微观的(孔隙率、电镜扫描)指标研究结石的抗侵蚀性能以及劣化规律。主要内容和结论如下:(1)软水侵蚀条件下粘土水泥浆的劣化规律研究。以CaO的累积溶出率作为评价指标,研究了常压固结条件下水灰比、粘土掺量、速凝剂掺量对浆材结石抗软水侵蚀性能的影响,试验表明,对粘土水泥浆材抗水溶蚀性能影响最大的是粘土掺量,为获得良好的抗软水侵蚀性能,粘土掺量不宜超过50%,速凝剂掺量不超过1%;通过自制的压滤装置模拟压滤效应下浆材的固结过程制作试件,研究压滤效应对结石抗溶蚀性能的影响,试验表明压滤效应能显著影响试件的固结和抗侵蚀性能,压滤条件下粘土水泥浆材的抗溶蚀性能提高幅度比纯水泥浆材的幅度大。(2)硫酸盐侵蚀条件下粘土水泥浆的劣化规律研究。采用强度和质量损失作为评价指标,将粘土掺量为0%、30%、50%的试件分别浸泡在清水和硫酸钠溶液中,测试龄期设置为30d、60d、90d、120d、150d。结果表明,侵蚀介质、侵蚀时间均影响粘土水泥结石的抗溶蚀性能及试件的劣化规律,粘土掺量为30%时浆材的抗硫酸盐侵蚀性能最优。(3)基于电镜扫描和吸水动力学法研究粘土水泥浆结石的微观特性。将成型的粘土水泥试件分别置于清水和标准养护箱中养护至规定龄期,用吸水动力学法测量结石的孔隙均匀系数和平均孔径,并用电镜扫描其微观形貌,辅助评价粘土水泥结石的抗侵蚀性能。结果表明,材料配比、养护龄期、养护条件均会对粘土水泥结石的孔隙特性产生影响,孔隙特性的观察结果与侵蚀试验的结论基本一致。
[Abstract]:Clay cement paste is a kind of inorganic grouting material with good stability, good impact resistance, friendly environment and a large amount of saving cement consumption. It is an ideal anti-seepage grouting material, and has been widely used in various fields of anti-seepage grouting engineering.It has been proved by engineering that the effect of seepage prevention and leakage plugging can meet the requirements of construction. However, the corrosion resistance of stone body determines its use effect and durability under the long-term action of soft water and other erosive solutions.It is of great significance to study the underground construction location which is hidden and belongs to the permanent project, the long service life and the anti-erosion performance of the slurry.In this paper, the deterioration mechanism of clay cement paste is analyzed, and combined with the soft water erosion test and sulfate resistance test of clay cement paste, the cumulative dissolution rate, mass loss rate, strength of macroscopical Cao and microcosmic (porosity) are analyzed.Electron microscope scanning (SEM) index was used to study the corrosion resistance and deterioration of stones.The main contents and conclusions are as follows: (1) study on the deterioration of clay cement slurry under soft water erosion.Taking the cumulative dissolution rate of CaO as the evaluation index, the effects of soil-cement ratio, clay content and accelerant content on the soft water corrosion resistance of slurry stones under normal pressure consolidation conditions were studied.The content of clay has the greatest influence on the water corrosion resistance of clay cement paste.The amount of clay should not exceed 50 and the quantity of accelerator should not exceed 1. The effect of pressure filtration on the corrosion resistance of stone was studied by simulating the consolidation process of slurry under the pressure filter effect by using a self-made pressure filter device.The results show that the pressure filtration effect can significantly affect the consolidation and corrosion resistance of the specimens.The corrosion resistance of clay cement paste under pressure filtration is larger than that of pure cement paste.The strength and mass loss were used as the evaluation indexes, and the samples with the clay content of 30% and 50% were immersed in water and sodium sulfate solution respectively, and the test age was set to be 30 days or 60 days or 90 days or 120 days or 150 days.The results show that the corrosion resistance of clay cement stones and the deterioration of specimens are affected by the erosion medium and time.Optimum Kraft erosion Resistance of slurry with 30% Clay content) the microscopic characteristics of clay cement paste stones were studied based on scanning electron microscopy and water absorption kinetics.The formed clay cement specimens were placed in clear water and standard curing box for curing to a specified age respectively. The porosity uniformity coefficient and average pore diameter of stone were measured by hydrodynamic method, and the microscopic morphology of stone was scanned by electron microscope.To evaluate the corrosion resistance of clay cement stone.The results show that the porosity characteristics of clay cement stones are affected by the ratio of materials, curing age and curing conditions, and the observation results of pore characteristics are basically consistent with the results of erosion test.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU578

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