Biomimetic agents and natural fibers are the promising combo to enhance the strength and self-healing efficacy of concrete infrastructures. However, their contribution in durability and fracture attributes of the host concrete matrix is still questionable. This study explores the use of sisal fiber reinforcement and Bacillus Subtilis to modify the fracture, shrinkage, and durability performance of concrete. Fracture response was analyzed in compression, tension and flexural followed by durability tests conducted for chloride penetration, water absorption, and acid resistance. Results revealed that the addition of Bacillus Subtilis increases stiffness, while sisal fiber imparts ductility to the concrete. The resulting mixture exhibited significant improvements in compressive strength (14.0%), split tensile strength (36.8%), flexural strength (30.9%), and bi-surface shear strength (25.4%) as compared to the control mixture. Additionally, the toughness indices of the resulting concrete improved under compressive, split tensile, and flexural loadings. Incorporating sisal fiber and Bacillus Subtilis into concrete mixtures also led to a notable reduction in linear shrinkage (58.9%), attributed primarily to the fiber-reinforcing effect. When sisal fiber and Bacillus Subtilis are combined in the concrete mix, there is a net improvement in the concrete's durability. The resulting blend exhibited an increase of 18.3%, 24%, and 14.1% in resistance to water absorption, chloride ion penetration depth, and acid attack, respectively, as compared to the control mixture. Micro-forensics endorsed the signatures of microbially-induced calcite precipitation in the concrete mixture, which contributed to add in the durability of the resulting matrix. The study demonstrated that the conjunctive use of Bacillus Subtilis and sisal fiber can yield durable and ductile concrete. The findings provide valuable insights into the use of biomimetic agents and natural fibers to enhance concrete fracture and durability attributes, with significant potential for practical applications in the construction industry.

仿生剂和天然纤维是提高混凝土基础设施强度和自愈功效的有前途的组合。然而，它们对主体混凝土基体的耐久性和断裂属性的贡献仍然值得怀疑。本研究探讨了使用剑麻纤维增强材料和枯草芽孢杆菌来改善混凝土的断裂、收缩和耐久性能。在压缩、拉伸和弯曲方面分析了断裂响应，然后进行了氯化物渗透、吸水性和耐酸性的耐久性测试。结果显示，添加枯草芽孢杆菌增加刚度，而剑麻纤维赋予混凝土延展性。与对照混合物相比，所得混合物在抗压强度 (14.0%)、劈裂抗拉强度 (36.8%)、弯曲强度 (30.9%) 和双面剪切强度 (25.4%) 方面表现出显着改善。此外，所得混凝土的韧性指数在压缩、劈裂拉伸和弯曲载荷下得到改善。将剑麻纤维和枯草芽孢杆菌掺入混凝土混合物中还导致线性收缩显着减少 (58.9%)，这主要归因于纤维增强效果。当剑麻纤维和枯草芽孢杆菌结合在混凝土混合物中，混凝土的耐久性得到净改善。与对照混合物相比，所得混合物的抗吸水性、氯离子渗透深度和酸侵蚀性分别提高了 18.3%、24% 和 14.1%。微取证证实了混凝土混合物中微生物诱导的方解石沉淀的特征，这有助于增加所得基质的耐久性。该研究表明，联合使用枯草芽孢杆菌剑麻纤维可以生产耐用且有延展性的混凝土。这些发现为使用仿生剂和天然纤维来增强混凝土断裂和耐久性属性提供了宝贵的见解，在建筑行业的实际应用中具有巨大潜力。