A study on the performance of concrete incorporated with microbial consortium

Abstract

Concrete is the most important material for building construction, but newlinecracks are unavoidable in concrete structures. Structural cracks not only newlineminimize the lifetime of the concrete structures but also reduce their strength, newlinedurability, and flexural behaviour. Traditional strategies are commonly used to newlinerepair cracks in concrete structures. However, these traditional rehabilitation newlinetechniques come with high maintenance costs and exacerbate challenges related newlineto environmental impacts and human health issues. The self-healing mechanism newlineof calcite-precipitating bacteria is harnessed to automatically repair micro-cracks. newlineMicro biologically Induced Calcite Precipitation (MICP) is utilized to fill the newlinecracks and voids in concrete. The self-healing capability of bacterial concrete newlineenables the rectification of cracks and helps in maintaining structural integrity newlinewhile reducing maintenance cost. This self-healing mechanism also plays a vital newlinerole in improving the lifetime of concrete structures. newlineThe aim of this present research is to develop microbial consortia derived newlinefrom conventional lime mortar and water collected from the curing site. The study newlineincludes isolation and identification of calcium carbonate precipitation bacteria newlinefrom microbial consortia and compares the suitability of the potential bacteria newlinefor use in concrete to enhance its strength and durability. Based on the results, newlinefour bacterial isolates, namely Bacillus Subtilis, Bacillus Cereus, Pseudomonas newlineAeruginosa, and Pseudomonas Otitidis, were chosen and identified using newline16S rRNA gene sequencing. These isolated bacterial strains were then compared newlinewith Bacillus Megaterium and Bacillus Licheniformis obtained from the newlineNational Dairy Research Institute (NDRI) in Karnal, India. newlineThe compressive strength of all four bacteria reached its maximum when newlineusing a bacterial cell concentration of 105 cells/ml of mixing water after 28 days. newlineAs a result, this concentration was deemed optimal and utilized in casting the newlinebacterial concrete specimens.