Cracking is inevitable in concrete due to its quasi-brittle nature. The presence of micro-cracks will not only impair concrete, but induce reinforcement corrosion by providing paths for the ingress of harmful species. In the past decades, a new technique to repair cracks automatically based on microbial induced carbonate precipitation has become attractive. This paper explored the crack healing potential of reinforced concrete incorporated with ureolytic type microbial self-healing agents immobilized in porous ceramsite particles. Effects of healing on the mechanical and electrochemical performances of reinforced concrete were investigated. The maximum crack width that could be healed completely by bacteria was up to 450 μm in 120 days. The highest regain ratios of flexural strength and modulus were achieved by bio-based healing when the initial damage degree was taken into account. As indicated by the Tafel polarization results, reinforcement corrosion was successfully inhibited by the crack closure from microbial precipitation without any side-effects.

由于混凝土具有准脆性，因此不可避免地会产生裂纹。微裂纹的存在不仅会损害混凝土，还会通过提供有害物质进入的途径而引起钢筋腐蚀。在过去的几十年中，一种基于微生物引起的碳酸盐沉淀自动修复裂缝的新技术变得具有吸引力。本文探讨了固定在多孔陶粒颗粒中的尿素型微生物自修复剂与钢筋混凝土的裂缝愈合潜力。研究了愈合对钢筋混凝土力学和电化学性能的影响。细菌可以完全治愈的最大裂缝宽度在120天内高达450μm。当考虑初始损伤程度时，基于生物的愈合获得了最高的挠曲强度和模量恢复率。如塔菲尔极化结果所表明的，由于微生物沉淀导致的裂纹闭合成功地抑制了钢筋腐蚀，而没有任何副作用。