Abstract This contribution presents an extensive performance evaluation of metakaolin-based geopolymer and calcium aluminate mortars during a long-term field exposure to a wastewater system exhibiting intensive microbially induced acid corrosion (MIAC) conditions. Results were compared to a high-performance OPC concrete, typically used for manhole fabrication. Field conditions were obtained by monitoring relative humidity, temperature, H2S and CO2. Microstructural degradation and elemental distributions within each binder type over time were recorded by electron probe microanalysis, X-ray diffraction and pH-imaging techniques, together with specimen's mass and surface-pH characterization. Microbiome and epifluorescence analyses indicated exposure-time dependent alternating bacterial community structures within the materials. Clear differences regarding bacterial species distribution and biodiversity were observed for the different binder types. Estimated corrosion rates were the lowest (1.4 mm/a) and the highest (13.3 mm/a) for the tested geopolymer formulations, pointing out that only well designed geopolymer materials may provide an improved MIAC resistance.

中文翻译：

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暴露于微生物引起的酸腐蚀的地质聚合物、铝酸钙和波特兰水泥基材料的长期原位性能

摘要 本论文对偏高岭土地质聚合物和铝酸钙砂浆在长期现场暴露于具有强烈微生物诱导酸腐蚀 (MIAC) 条件的废水系统中进行了广泛的性能评估。结果与通常用于制造检修孔的高性能 OPC 混凝土进行了比较。现场条件是通过监测相对湿度、温度、H2S 和 CO2 获得的。通过电子探针微量分析、X 射线衍射和 pH 成像技术以及样品的质量和表面 pH 表征，记录了每种粘合剂类型随时间的微观结构降解和元素分布。微生物组和落射荧光分析表明材料内的暴露时间依赖性交替细菌群落结构。对于不同的粘合剂类型，观察到细菌物种分布和生物多样性的明显差异。测试的地质聚合物配方的估计腐蚀速率最低 (1.4 mm/a) 和最高 (13.3 mm/a)，指出只有设计良好的地质聚合物材料才能提供改进的 MIAC 抗性。