微生物诱导矿化材料耐候性能试验研究

发布时间：2018-04-02 14:30

本文选题：微生物诱导矿化技术　切入点：耐酸雨性能　出处：《内蒙古工业大学》2017年硕士论文

【摘要】：当今社会,随着城镇化的发展,人们对土地的需求不断增加。传统的化学灌浆方法和化学固化剂对环境造成不良影响。目前,利用微生物诱导矿化技术生成一种绿色、无污染的新材料正脱颖而出,这种材料是利用微生物自身新陈代谢作用生成碳酸钙固结环境中的砂土。这种新材料正逐步被研究和开发,将这种矿化技术应用于土地改良和地基处理,可能在不远的将来带来巨大的环境和经济效益。随着季节的变化,在不同地区对这种微生物诱导矿化土工材料的耐候性能提出挑战。新型材料的耐酸雨、耐冻融、耐干湿性能是材料耐候性的重要内容。通过对该材料耐候性能的一系列研究,为这种材料日后的应用和推广提供了理论和试验依据。本试验包括:确定这种人工合成矿化土工材料的最佳固化时间、渗透系数;通过质量损失、饱和含水率变化以及力学试验,对这种微生物诱导矿化土工材料的耐酸雨、耐冻融(水冻、盐冻)和耐干湿(水溶液干湿循环、盐溶液干湿循环)进行一系列的试验研究。试验结果表明:标准砂作基质土的细菌诱导矿化材料最佳固化时间是7d;微生物矿化后生产的MICP-标准砂试样具有一定强度,渗透性远大于混凝土渗透性,具有较高饱和含水率。MICP-标准砂试样的耐酸雨腐蚀能力差,随着酸雨酸性增加,材料的耐酸性能下降;该材料耐冻性和耐干湿破坏能力差,环境中氯盐提高该材料的耐冻性能;环境中存在氯盐和Na_2SO_4会降低材料的耐干湿性能。
[Abstract]:Nowadays, with the development of urbanization, people's demand for land is increasing.Traditional chemical grouting methods and chemical curing agents have adverse effects on the environment.At present, a green and pollution-free new material is produced by microbial induced mineralization, which is a kind of sand soil in the environment of calcium carbonate consolidation, which is formed by the metabolism of microorganism itself.This new material is gradually being studied and developed. The application of this mineralized technology to land improvement and foundation treatment may bring great environmental and economic benefits in the near future.With the change of seasons, the weathering resistance of this kind of microorganism induced mineralized geotechnical materials is challenged in different regions.The acid rain resistance, freezing and thawing resistance, dry and wet resistance of new materials are important contents of weathering resistance.Through a series of studies on the weathering resistance of this material, it provides theoretical and experimental basis for its application and popularization in the future.This experiment includes: determine the best curing time, permeability coefficient of the synthetic mineralized geotextile, through mass loss, change of saturated moisture content and mechanical test, induce acid rain resistance of the mineralized geotextile to this kind of microorganism,A series of experiments were carried out on freezing and thawing (water freezing, salt freezing) and dry and wet (aqueous solution dry and wet cycle, salt solution dry and wet cycle).The test results show that the best solidification time of the bacteria-induced mineralizing material for standard sand is 7 days, and the MICP- standard sand sample produced after microbial mineralization has a certain strength, and the permeability is much greater than that of concrete.The acid rain corrosion resistance of the sample with high saturated moisture content. MICP- standard sand is poor, with the increase of acid rain acidity, the acid resistance of the material decreases, the freezing resistance and the dry and wet failure resistance of the material are poor, and the freezing resistance of the material is improved by chloride salt in the environment.The presence of chloride and Na_2SO_4 in the environment will reduce the dry and wet resistance of the materials.
【学位授予单位】：内蒙古工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB302

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