基于微生物矿化沉积的裂缝自修复混凝土微观及物相分析

Microscopic and phase analysis on crack self-healing capacity of concrete based on microbial mineralization deposition

作为一种新型的混凝土裂缝修复技术,基于微生物矿化沉积的裂缝自修复技术具有裂缝自诊断自修复、能够实现裂缝的长期有效修复等特点。以膨胀珍珠岩为载体,以好氧微生物科氏芽孢杆菌为自修复剂,制备具有裂缝自修复功能的混凝土,并通过裂缝宽度观测、SEM及XRD等方法分析其修复效果。结果表明:膨胀珍珠岩的空腔可为孢子提供足够的生存空间以及良好的附着点;经修复养护后,微生物自修复混凝土在宏观与微观上均表现出较好的裂缝修复效果;XRD分析表明,微生物自修复混凝土在裂缝处的矿化产物为方解石。

As a new type of crack-healing technique,self-healing technique based on microbial mineralization deposition can realize the self-diagnosis and self-healing capacity, as well as achieving long-term effective repair of concrete cracks. In this study, aerobic bacteria-Bacillus cohnii and expanded perlite were used as self-healing agent and agent cartier respectively, and a new type of self-healing concrete is subsequently prepared. Moreover, crack width measurement, SEM analysis and X-ray diffraction analysis were conducted to evaluate the crack healing efficiency. It shows that the cavities on the expanded perlite particles not only can provide sufficient living spaces but also are good attachment points for the bacterial spores. After healing cured,bacteria- based self-healing concrete macroscopically and microscopically exhibited better efficiency of crack-healing capacity. It shows from XRD analysis that the mineral precipitation collected in the cracks of bacteria-based concrete was calcite.