混凝土裂缝的微生物自修复效果

Microbial self-healing effects of concrete cracks

利用裂缝测宽仪、扫描电镜和热重分析技术分别对混凝土裂缝的微生物自修复效果进行了研究.研究结果表明:修复40 d后,混凝土裂缝就可以被微生物矿化形成的碳酸钙所填充,修复效果明显,最大填充宽度超过1 mm.微生物矿化形成的碳酸钙在裂缝开口处最多,且随着裂缝深度的增加碳酸钙逐渐减少,当混凝土裂缝深度超过10 mm时未发现微生物形成的碳酸钙.距离裂缝断裂面表层1.5 mm内,微生物可矿化形成较多碳酸钙.而当超过1.5 mm时,由于该微生物矿化需要氧气,因此,随着距离裂缝断裂面表层越远、距离水泥基体越近,微生物矿化形成的碳酸钙含量越来越少.

The effect of crack self-healing was studied in bacterial concrete by the crack width gauge,scanning electron microscopy and thermogravimetric analysis.The results indicate that after concrete is cured for 40 d,concrete cracks can be filled with calcium carbonate produced by microbial mineralization.The self-healing effect is obvious and the maximum width is greater than 1 mm.The quantity of calcium carbonate is the largest in the openings of concrete crack.And calcium carbonate is gradually reduced with the increase in the crack depth.When the concrete crack depth is over 10 mm,the formation of calcium carbonate is no longer found.When the distance is less than 1.5 mm,microorganisms can produce a large amount of calcium carbonate through mineralization.However,when the distance is greater than 1.5 mm,the content of calcium carbonate gradually reduces with the increase in the depth.The reason is that the microbial mineralization requires oxygen.