Existing research has inadequately addressed the synergistic effects of microorganisms and admixtures in promoting self-healing behavior and mechanisms of cracks in marine environments, including the atmospheric zone, tidal-splash zone, and submerged zone. This study primarily involved the incorporation of multiple admixtures and microorganisms into cement to prepare two types of biogenic mortars: -based mortar (BPM) and -based mortar (BSM), with ordinary mortar (OM) serving as the control group. The mechanical properties, electrical flux, and pore structure of the mortars were investigated. Additionally, the self-healing behavior and mechanisms of cracks were studied under atmospheric, tidal-splash, and submerged conditions. The results indicate that with increasing curing age, the synergistic effect of admixtures and microorganisms continuously refined the pore structure of the specimens and enhanced their flexural strength, compressive strength, and resistance to chloride ion penetration. The atmospheric environment was found to be unfavorable for the self-healing of cracks in the specimens. However, in the submerged and tidal-splash zones, the combined action of microorganisms and admixtures led to more pronounced self-healing phenomena in the biogenic mortars compared to OM. Particularly, the self-healing effect of BSM cracks was more pronounced in the tidal-splash zone, with a 100% self-healing efficiency observed after 53 days. This was attributed to the ability of microorganisms in the tidal-splash zone to induce calcium carbonate precipitation on the surface of cracks in admixture-modified cementitious materials, thereby reducing the penetration of seawater, CO, and O into the cracks, lowering the carbonation reaction of Ca(OH) crystals, and reducing the formation of brucite crystals inside the cracks, consequently enhancing the water permeability resistance of the specimens. These research findings hold significant engineering implications for improving the durability and service life of coastal self-healing concrete structures.

中文翻译：

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微生物与多种外加剂协同作用提高不同海洋环境下生物砂浆裂缝自修复能力

现有的研究还没有充分解决微生物和混合物在促进海洋环境（包括大气区、潮汐溅区和水下区）裂缝自修复行为和机制方面的协同效应。本研究主要涉及在水泥中掺入多种外加剂和微生物，制备两种类型的生物砂浆：β基砂浆（BPM）和β基砂浆（BSM），并以普通砂浆（OM）作为对照组。研究了砂浆的机械性能、电通量和孔隙结构。此外，还研究了大气、潮汐飞溅和水下条件下裂纹的自愈行为和机制。结果表明，随着养护龄期的增加，外加剂和微生物的协同作用不断细化试件的孔隙结构，增强其抗折强度、抗压强度和抗氯离子渗透能力。研究发现大气环境不利于试件裂纹的自修复。然而，在水下和潮汐飞溅区，微生物和外加剂的共同作用导致生物砂浆比 OM 具有更明显的自愈现象。特别是，BSM裂缝的自愈效果在潮汐浪涌区更为明显，53天后自愈效率达到100%。这是由于潮溅区微生物能够诱导外加剂改性胶凝材料裂缝表面碳酸钙沉淀，从而减少海水、CO和O向裂缝的渗透，降低碳化反应Ca(OH)晶体的形成，减少裂纹内水镁石晶体的形成，从而提高试件的抗渗水性能。这些研究结果对于提高沿海自修复混凝土结构的耐久性和使用寿命具有重要的工程意义。