Bio-Based Self-Healing Concrete for Sustainable and Durable Concrete Infrastructure

Abstract

In this study, bio-self-healing concrete was manufactured using a natural phenomenon called microbial-induced calcium carbonate precipitation (MICP). The bacillus cereus bacteria isolated from Qatari soil was used for this purpose. These bacteria have endured the harsh weather of high temperatures, humidity, and alkaline soil conditions. Hence, are a potential candidate for long-term self-healing in concrete structures that are subjected to the climate of the Middle Eastern region. The bacteria were encapsulated in sodium alginate beads then the beads were added to the cement-sand mortar. The nutrients for bacteria such as urea, calcium nitrate, yeast extract, and calcium chloride were mixed in mortar as dry constituents. After curing for 28 days, cracks were artificially induced in the prismatic samples, which were reinforced with steel rebars at the tensile side. Samples were placed in water to instigate self-healing. It was observed that the bacteria healed the cracks up to 0.70 mm. It is concluded that the used bacteria are viable in the alkaline concrete matrix and capable of producing calcium carbonate.