Akademik Veri Yönetim Sistemi
CEMENT & CONCRETE COMPOSITES, 2024 (SCI-Expanded)
Existing studies on microbial self -healing concrete often employed an arbitrary approach to the initial amount of healing agents, leading to significant performance variations. The amount of bacteria becomes a crucial parameter affecting the overall cost of the material. Therefore, assessing the effect of initial bacteria content on microbial self -healing performances is essential. This study presents the variation of self -healing performances of biomortars with initial bacteria content ranging from 0.05 % to 2.50 % (0.07 % -3.20 % biogranule) w/w cement. All biomortars outperformed the crack healing performance of abiotic control specimens. The net contribution of microbial healing ( MH net ) was determined by analysing autogenous healing and microbial healing periods separately. The variations in initial bacteria content did not significantly affect MH net which could reach up to 125 mu m in 2 -weeks of water immersion. The minimum effective bacteria dosage in the form of biogranules for developing microbial self -healing concrete was determined as 0.05 % bacteria w/w cement with an overall crack healing limit of 300 mu m. Microbial healing of cracks up to 300 mu m crack width led to 50 -80 % higher water tightness regain compared to the autogenously healed specimens. The purity of CaCO 3 minerals sealing the cracks decreased with the increasing initial bacteria content of the biomortars. Overall, the initial bacteria content did not significantly affect the microbial self -healing performance in the tested dosage range. At the minimum effective bacteria dosage, consistent self -healing of cracks up to 300 mu m became possible at the expense of approximately 20 % increase in the overall cost of the material.