In marine engineering, infrastructures are facing serious issues of deterioration resulted largely from concrete cracking due to the hostile seawater environment. Microbial induced carbonate precipitation (MICP) is an effective and environmentally friendly way to achieve self-healing of concrete cracks. However, the formation and structure of MICP products for crack healing in seawater remain unclear, thus hindering the application of MICP in self-healing of marine structures. By means of experimental and thermodynamic approaches, this work first investigated the evolution of aqueous species as well as the phase assemblages and microstructures of bio-minerals in compound solutions simulating concrete cracks in seawater. The coupling effects of Mg²⁺ and bacteria on bio-mineralization kinetics result in significant discrepancy between experimental results and thermodynamic outputs in terms of phase assemblages in seawater, yet the morphology depends on Mg²⁺ rather than bacteria. A comparative analysis on healing products collected from real concrete cracks in seawater revealed a fast abiotic precipitation of brucite followed by the MICP process, which is more conducive to attain a high-efficient self-healing in marine environment.

在海洋工程中，恶劣的海水环境导致基础设施面临严重的老化问题，主要原因是混凝土开裂。微生物诱导碳酸盐沉淀（MICP）是实现混凝土裂缝自修复的有效且环保的方法。然而，用于海水中裂纹修复的MICP产物的形成和结构仍不清楚，从而阻碍了MICP在海洋结构自修复中的应用。通过实验和热力学方法，这项工作首先研究了模拟海水中混凝土裂缝的复合溶液中水物质的演化以及生物矿物的相组合和微观结构。^{Mg 2+}和细菌对生物矿化动力学的耦合作用导致实验结果与海水中相组合的热力学输出之间存在显着差异，但形态取决于Mg ²⁺而不是细菌。对海水中真实混凝土裂缝收集的修复产物进行比较分析，发现水镁石快速非生物沉淀，然后进行 MICP 过程，更有利于在海洋环境中实现高效的自修复。