A Comparative Study of Sustainable Bacteria-Alccofine Concrete: Environmental Benefits and SEM Analysis

The potential for creating unique, environmentally friendly, and cost-effective concrete via biomineralization is discussed in this research. Cement, a necessary component of concrete, is expensive and emits between 8 and 10% of the world’s CO2 emissions. Researchers have significant effects to identify alternatives that can reduce the burden of high costs, excessive energy use, and environmental repercussions. Manufactured sand (M-sand) completely replaced fine aggregate, and cement was replaced with alternatives such as Alccofine (AF) and Silica Fume (SF). The percentage at which it can be substituted for cement is, however, somewhat small. The goal of this study is to create an environmentally friendly AF and SF concrete mix by incorporating bacteria with the highest possible cell concentration. To evaluate the mechanical properties, concrete samples were tested for flexural strength, split tensile strength, and compressive strength at 7, 14 and 28 days postcuring. The microstructural analysis of sustainable concrete was performed using scanning electron microscopy (SEM) techniques. It was determined that 10% alccofine and 15% silica fume by volume of cement in the binary cementitious system provided the best mechanical characteristics for bacterial concrete using Bacillus megaterium. Similarly manner in the ternary cementitious system, the highest gain in compressive strength is seen when 10% alccofine is substituted with 10% silica fume in the cement mixture. Calcium carbonate precipitation validated the enhanced properties of bacterial concrete. The microorganisms used in the concrete are non-toxic and environmentally being. Results indicate that using Bacillus megaterium alongside AF and SF helps to reduce cement usage, lessens carbon dioxide emissions, and makes concrete more environmentally friendly. Using Scanning Electron Microscopy (SEM), the calcite precipitations in bio-additive mixed ternary admixture blended concrete were confirmed. The proposed regression equations produced minimal errors when compared to the experimental results, thus providing accurate and effective predictions of the flexural, split, and compressive strengths. The strength properties of these blends were validated through SEM studies.