Durability of concrete exposed to laboratory-simulated marine microbe-induced corrosion
Durability of concrete exposed to laboratory-simulated marine microbe-induced corrosion
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DOI：
10.1016/j.conbuildmat.2023.132563
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发表时间：
2023-10
影响因子：
7.4
通讯作者：
Zhihua Liu;Liqin Gan;H. Rong
中科院分区：
文献类型：
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作者：
Zhihua Liu;Liqin Gan;H. Rong
诱导微生物引起的腐蚀，以评估混凝土在海水中的耐久性。在含硫代硫酸盐的海水介质中，对含硫氧化菌的生物试验组（BTG）和不含硫氧化菌的非生物对照组（ACG）试样进行8个月的腐蚀。微生物对混凝土的侵蚀是通过pH值和硫酸根离子浓度的变化来确定的。ACG表面轻微风化和破碎，而BTG试样严重恶化，沿边缘沿着有点蚀和材料损失。8个月后，BTG培养基的pH值从11.4降至9.65，中和深度为12.4 mm：分别约为ACG的1.75和2.3倍。经过100次冻融循环后，ACG试件具有较好的抗冻性。生物膜对进入的离子具有选择性，减缓了氯离子的渗透，BTG样品具有更好的抵抗力。此外，XRD，SEM和电化学阻抗（EIS）分析表明，生物硫酸引起混凝土的水化产物的溶解和硫酸盐矿物的结晶膨胀和孔隙率增加，导致混凝土劣化。
Laboratory-simulated, microbially induced corrosion was induced to assess concrete durability in seawater. Biotic test group (BTG) specimens with sulphur-oxidizing bacteria (SOB) and abiotic control group (ACG) specimens without SOB were corroded for 8 months in seawater medium containing thiosulphate. Concrete erosion by microorganisms was determined by changes in pH and sulphate ion concentrations. The ACG surfaces were slightly weathered and broken, while the BTG specimens were severely deteriorated, with pitting and material losses along the edge. After 8 months, the pH of the BTG medium decreased from 11.4 to 9.65, and its neutralisation depth was 12.4 mm: approximately 1.75 and 2.3 times, respectively, that of ACG. The ACG specimens had better frost resistance after 100 freeze–thaw cycles. The biofilm was selective for incoming ions and slowed chloride ion penetration, with the BTG specimens having better resistance. Additionally, XRD, SEM, and electrochemical impedance (EIS) analyses showed that the biological sulphuric acid caused concrete dissolution of hydration products and crystalline swelling of sulphate minerals and increased porosity, leading to concrete deterioration.