Abstract

Recent research, in the field of structural durability and longevity has raised the interests in the precipitation of calcium carbonate (CaCO₃) by certain bacterial strains. Use of bacteria as a self-healing material via bio mineralisation is a natural healing process which heals crack by mineral precipitation. The microbiologically induced precipitation accelerates at different rates at different conditions. Therefore, this environmental study was aimed at finding the best curing media, possibility to apply Bacillus megaterium integrated into mortar matrix to act as a self-healing agent to seal the crack at a 10⁵ cells/ml concentration by subjecting the mortar cubes to varying temperature conditions. The change in properties of mortar cubes with change in curing media, days of curing and range of Bacillus solution added were analysed. The results were compared with the conventional ones cured in different media. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) confirms the microbiologically induced mineral precipitation. Mortar cubes are cracked and evaluated visually for successive days to find the healing efficiency. The conclusions of the paper suggest promising application of self-healing mortar cubes at different geographical locations by varying the amount of bacterial solution.

摘要

最近在结构耐久性和寿命领域的研究引起了人们对某些细菌菌株沉淀碳酸钙 (CaCO _{3 ) 的兴趣。}通过生物矿化使用细菌作为自愈材料是一种自然愈合过程，通过矿物沉淀来治愈裂缝。微生物诱导的沉淀在不同条件下以不同的速率加速。因此，这项环境研究旨在寻找最佳的固化介质，将巨大芽孢杆菌应用到砂浆基质中作为自愈剂在 10 ^{5下密封裂缝的可能性。}通过将研钵立方体置于不同的温度条件下，细胞/毫升浓度。分析了砂浆立方体的性能随养护介质、养护天数和添加芽孢杆菌溶液范围的变化而变化。将结果与在不同介质中固化的常规结果进行比较。X 射线粉末衍射 (XRD) 和扫描电子显微镜 (SEM) 证实了微生物诱导的矿物沉淀。连续几天将砂浆立方体开裂并目视评估以发现愈合效率。该论文的结论表明，通过改变细菌溶液的量，可以在不同的地理位置应用自愈砂浆立方体。