Biogenic approach for concrete durability and sustainability using effective microorganisms: a review

Abstract

Over the past few years, concrete durability has attracted much attention from researchers. The demand for durable and sustainable concrete is on the rise due to the daily increase in global greenhouse gas (GHG) emissions and global warming. This has necessitated the use of chemical admixtures as ingredients to improve the fresh and hardened properties of concrete. However, these admixtures are associated with drawbacks, like high cost, coloration, GHG, and rapid shrinkage, among others, all of which are limitations to its sustained use. Biogenic methods in concrete production are now being harnessed due to their relatively low cost, high sustainability, and greenness. One such method is the use of effective microorganisms (EM). The coexistence of these microorganisms propels modifications through the biosynthesis of metabolites, which prolongs their existence. However, their mechanism of interaction in concrete is still unclear. Some reviews have been presented on EM concrete; however, these reviews have focused specifically on the hydration characteristics and mechanical properties of concrete. This paper presents a comprehensive review and up-to-date findings of the use of EM in concrete. The EM types, constituents, and preparation procedures are discussed in-depth, as are the influences of EM on the mechanical properties, durability properties, and microstructure of concrete. In addition, recommendations for further research are highlighted. This review shows that EM can be utilized to improve the strength and durability of concrete.