Reinforcement corrosion and the concrete strength reduction are critical problems that resulted from crack creation in concrete. Very expensive and hazardous technologies based on chemical materials have been provided for repairing the cracks. Recently, crack repair using bio-catalysis precipitating bacteria has been developed as a viable and ecofriendly alternative technique. The main target of this study was to select and identify bacterial isolates with high urease activity to use in filling the cracks by the precipitation of CaCO3. Two endospore-forming and alkali-resistant ureolytic bacteria were combined with concrete to tolerate the mechanical stresses generated by mixing. The two isolates designated as (B1 and B2) were selected and identified as Bacillus wiedmannii strain FSL W8-0169 and Bacillus paramycoides strain MCCC 1A04098, respectively, using 16SrDNA gene sequencing. Both bacterial species completely heal cracks in fully destructed concrete and significant enhancement in compressive strength was illustrated. The calcite filling of cracks and CaCO3 crystals that were screened using a scanning electron microscope may explain the crack healing and the enhancement in concrete strength. Bacillus wiedmannii strain FSL W8-0169 and Bacillus paramycoides strain MCCC 1A04098 can be inserted with the concrete to improve the compressive strength and the self-healing of cracks. The two ureolytic bacterial strains can be used to protect water buildings from exposure to frequent cracks.

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分离的解脲芽孢杆菌对混凝土裂缝生物愈合的影响

钢筋腐蚀和混凝土强度降低是混凝土裂缝产生的关键问题。已经提供了基于化学材料的非常昂贵且危险的技术来修复裂缝。最近，使用生物催化沉淀细菌的裂缝修复已被开发为一种可行且环保的替代技术。本研究的主要目标是选择和鉴定具有高脲酶活性的细菌分离物，用于通过沉淀 CaCO3 填充裂缝。两种内生孢子形成和耐碱尿素分解细菌与混凝土结合，以耐受混合产生的机械应力。选择命名为 (B1 和 B2) 的两个分离株，并鉴定为威氏芽孢杆菌 FSL W8-0169 和副真菌芽孢杆菌菌株 MCCC 1A04098，分别采用 16SrDNA 基因测序。两种细菌都可以完全愈合完全破坏的混凝土中的裂缝，并说明了抗压强度的显着提高。使用扫描电子显微镜筛选出的方解石填充裂缝和 CaCO3 晶体可以解释裂缝愈合和混凝土强度的提高。维德曼芽孢杆菌 FSL W8-0169 和副真菌芽孢杆菌 MCCC 1A04098 可以与混凝土一起插入，以提高抗压强度和裂缝的自愈能力。这两种尿素分解细菌菌株可用于保护水建筑免受频繁裂缝的影响。使用扫描电子显微镜筛选出的方解石填充裂缝和 CaCO3 晶体可以解释裂缝愈合和混凝土强度的提高。维德曼芽孢杆菌 FSL W8-0169 和副真菌芽孢杆菌 MCCC 1A04098 可以与混凝土一起插入，以提高抗压强度和裂缝的自愈能力。这两种尿素分解细菌菌株可用于保护水建筑免受频繁裂缝的影响。使用扫描电子显微镜筛选出的方解石填充裂缝和 CaCO3 晶体可以解释裂缝愈合和混凝土强度的提高。维德曼芽孢杆菌 FSL W8-0169 和副真菌芽孢杆菌 MCCC 1A04098 可以与混凝土一起插入，以提高抗压强度和裂缝的自愈能力。这两种尿素分解细菌菌株可用于保护水建筑免受频繁裂缝的影响。