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

Abstract

The potential for creating unique, environmentally friendly, and cost-effective concrete via bio mineralization 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. At 7, 14, and 28 days after curing, the concrete samples were examined for compressive strength, split tensile strength, and flexural strength were performed to analyze the mechanical properties. Scanning electron microscope (SEM) techniques were used for the microstructural examination of sustainable concrete. It was determined that 10% alccofine and 15% silica fume by volume of cement in the binary cementitious system provided the best mechanical characterizes 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 microorganism used in the concrete is 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. The calcite precipitations of bio-admixture mixed ternary admixture blended concrete were confirmed by Scanning Electron Microscopy (SEM). When compared to the findings of the experiments, the proposed regression equations produce relatively minor errors; as a result, they are capable of producing predictions of the flexural, split, and compressive strengths that are accurate and efficient. The SEM analyses confirm the strength characteristics of these mixes.