Microbial Technology—A Sustainable Alternative to Improve Concrete Quality

Abstract

Concrete has become the world’s most broadly utilized building material due to its adaptability, solidness, sustainability, and economy. Traditional concrete generally refers to the mixture of aggregates, i.e., sand and stone chips, and held firmly by a binder of cementitious paste. Different supplementary cementitious materials have already been developed by researchers to improve quality of concrete. However, the present study is only centered with traditional cement-based concrete with a biogenic self-healing system. Generally, a biological agent with culture media is consolidated in concrete which gives rise to a modified concrete termed as “microbial concrete.” Microbial concrete technology can improve concrete quality effectively through bio-mineralization process. The aim of the present work is to promote eco-friendly biological agents to enhance concrete quality. A pre-fixed culture density (0.5 ± 0.1) was maintained for preparing three different grades of concrete (20, 30 and 40 MPa). The effects of two bacterial strains, i.e., Bacillus cereus and Escherichia coli, were studied on mechanical properties of concrete. Five different ratios of plain water to microbial culture were added to concrete matrix to investigate the effect of microbial percentage. The study result reveals that the uses of Bacillus strain are more effective than Escherichia strain regarding concrete strength development. Out of the five ratios, 25:75 (plain water to microbial culture) is found maximum effects on concrete consolidation.