A common approach to enhance the self-healing behaviour of cracked backfill is through the addition of carriers, but this practice can potentially disrupt the overall performance of the backfill and pose environmental concerns. Overcoming the limitations of traditional carrier-based methods to improve self-healing efficiency has been a challenging task. This study proposed an environmentally friendly approach to enhance the healing ratio of cracked backfill without the need for additional carriers. Specifically, a mixture of aerobic and anaerobic bacteria was pre-embedded in polypropylene-fiber reinforced backfill. The self-healing capacity of the cracked backfill was systematically evaluated in terms of crack width and area healing efficiency, strength recovery ratio, permeability coefficient, and water absorption. The results showed that the incorporation of mixed bacteria in the backfill resulted in an area healing ratio of 44.71% and a strength recovery ratio of 30.88%. The mixed bacteria had a higher biomineralization ratio compared to the noted single strain, suggesting its enhanced capacity in self-healing. Also, the mixed bacteria exhibited higher sustainability in self-healing. These findings provide compelling evidence that the self-healing ratio of cracked backfill can be improved through a benign approach that only involves pre-embedding mixed bacteria without the use of additional carriers.

增强开裂回填自愈行为的一种常见方法是通过添加载体，但这种做法可能会破坏回填的整体性能并引起环境问题。克服传统基于载体的方法的局限性以提高自愈效率一直是一项具有挑战性的任务。本研究提出了一种无需额外载体即可提高裂缝回填愈合率的环保方法。具体来说，将好氧和厌氧细菌的混合物预埋在聚丙烯纤维增强回填土中。从裂缝宽度和面积愈合效率、强度恢复率、渗透系数和吸水率等方面系统评价了裂缝回填体的自愈合能力。结果表明，在回填土中掺入混合菌后，面积愈合率为44.71%，强度恢复率为30.88%。与所述单一菌株相比，混合细菌具有更高的生物矿化率，表明其增强的自我修复能力。此外，混合细菌在自我修复方面表现出更高的可持续性。这些发现提供了令人信服的证据，表明可以通过仅涉及预嵌入混合细菌而不使用额外载体的良性方法来提高破裂回填物的自愈率。表明其增强的自我修复能力。此外，混合细菌在自我修复方面表现出更高的可持续性。这些发现提供了令人信服的证据，表明可以通过仅涉及预嵌入混合细菌而不使用额外载体的良性方法来提高破裂回填物的自愈率。表明其增强的自我修复能力。此外，混合细菌在自我修复方面表现出更高的可持续性。这些发现提供了令人信服的证据，表明可以通过仅涉及预嵌入混合细菌而不使用额外载体的良性方法来提高破裂回填物的自愈率。