\r练继建¹，王昶力¹，闫 玥¹，付登锋¹，齐 浩\r²\r
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AuthorsHTML:\r练继建¹，王昶力¹，闫 玥¹，付登锋¹，齐 浩\r²\r
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AuthorsListE:\rLian Jijian ¹，Wang Changli ¹，Yan Yue ¹，Fu Dengfeng ¹，Qi Hao \r²\r
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AuthorsHTMLE:\rLian Jijian ¹，Wang Changli ¹，Yan Yue ¹，Fu Dengfeng ¹，Qi Hao \r²\r
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Unit:\r1. 天津大学水利工程仿真与安全国家重点实验室，天津 300072；
2. 天津大学系统生物工程教育部重点实验室，天津 300072\r
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Unit_EngLish:\r1. State Key Laboratory of Hydraulic Engineering Simulation and Safety，Tianjin University，Tianjin 300072，China；
2. Key Laboratory of Systems Bioengineering of Ministry of Education，Tianjin University，Tianjin 300072，China\r
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Abstract_Chinese:\r微生物修复技术所需的菌液流动性好，修复过程中微生物代谢物与水泥基材料有着良好的相容性和界面强度，因此，具备能耗低、绿色环保、施工简便的潜力．针对微生物修复混凝土裂缝问题，通过试验研究了环境碱度对细菌生长和微生物矿化的影响，探讨了胶结溶液的最优浓度配比和胶结时间，并将这些参数运用于后续微生物修复混凝土裂缝的试验中．试验中考虑了裂缝表观形状(裂缝深度、宽度及延伸角度)的差异，观察了碳酸钙沉淀的沉积方式，并采用X 射线衍射仪(XRD)和扫描电子显微镜(SEM)手段监测其沿裂缝界面的晶体组成和形貌．结果表明：菌体自身对环境碱性突变具有自适应能力，当环境碱性并非过高时(pH≤12)，菌体在生长代谢过程中能够驱使环境pH 值向着最适宜菌体自身生长的pH 值(约为8.7)发展；快速诱导碳酸钙沉积修复混凝土裂缝的最佳胶结液有效浓度为0.83 mol/L，最优微生物矿化间隔时间为5 h；裂缝表观形状的差异导致细菌在裂纹表面上的吸附不均匀性，其中裂缝的宽度不直接影响微生物修复的机理，而裂缝深度和裂缝倾角会影响碳酸钙沉淀的均匀性；使用注射和漫灌胶结液的方式修复具有不同表观形状的裂缝的混凝土最好的修复效果能将混凝土的渗透性降低4 个数量级(从10^-4 m/s到10^-8 m/s)．\r
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Abstract_English:\rThe bacteria suspensions utilized for microbially induced carbonate precipitation method exhibit high fluidity. Moreover，mineralized metabolites are highly compatible with cement-based materials，which ultimately leads to great interfacial strength during concrete crack repair process. Therefore，microbial remediation is characterized by low energy consumption，environmental safety，and simplicity. Considering the microbial remediation of concrete cracks，an experimental research was conducted on the effects of environmental alkalinity on bacterial growth and microbial mineralization，and the optimum concentration ratios of cemented solution and cementation time were determined. Then these parameters were applied to subsequent experiments of microbial remediation of concrete cracks. Considering the difference in the apparent shape of the crack(depth，width，and elongation angle)，the deposition mode of calcium carbonate precipitation in the process of experiment was observed and its crystal composition and morphology along the fracture interface were observed by X-ray diffractometer (XRD) and scanning electron microscope (SEM). The results show that the utilized bacteria possess the ability to adapt to environmental mutations. When the environment was not highly alkaline(pH≤12)，the bacteria could reduce the pH of the surroundings to the optimum value(around 8.7)during the growth and metabolism stages. An operative concentration of cementing solution of 0.83 mol/L and microbial mineralization time of 5 h were recommended as the optimum parameters for the microbial-remediated crack in concrete. The difference in the apparent shapes of cracks led to the inhomogeneity of bacterial adsorption on the crack surface. The crack width did not directly affect the mechanism of microbial remediation；however，the crack depth and the inclination angle of crack affected the bacterial distribution along the crack surface. The use of the injective and immersing cementation to repair concrete with different shapes of cracks can reduce the permeability of concrete by four orders of magnitude(from 10-4 m/s to 10-8 m/s)under optimum conditions.\r
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Keyword_Chinese:混凝土；裂缝；微生物诱导碳酸钙沉淀；修复；渗透性\r

Keywords_English:concrete；crack；microbially induced carbonate precipitation；repair；permeability\r


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