Self-Healing Concrete Utilizing Ureolysis Mechanism of Microbially Induced Calcite Precipitation (MICP): a Review

• Published in: Iranian Journal of Science and Technology - Transactions of Civil Engineering
• Main Author: Kho Y.S.; Wong K.S.; Pauzi N.N.M.; Joo M.S.; Hadibarata T.
• Format: Review
• Language: English
• Published: Springer Science and Business Media Deutschland GmbH 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85208117535&doi=10.1007%2fs40996-024-01660-x&partnerID=40&md5=561a84e1bcb784d0195527617df8b5d6

Concrete is the most broadly implemented construction material globally because of its high availability, strength, durability attributes, and low cost, thus concrete health is considered a significant factor from the structural perspective. However, cracks are unavoidable in concrete and hence will cause corrosion in reinforcement and thus influence durability and may lead to serious structural issues. Therefore, microbial technology is chosen among the different types of autonomous healing as the concrete strength characteristics can be improved through the addition of microorganisms and can heal the cracks efficiently and automatically with the presence of moisture and precursors. Ureolysis is the primary selected and most implemented heterotrophic pathway for microbially induced calcite precipitation (MICP) because ureolysis is the most uncomplicated and can produce the most calcium carbonate precipitation to heal the microcracks. Generally, this paper provides a comprehensive overview of the literature on self-healing concrete utilizing ureolysis mechanism of MICP. As a result, the outcomes and challenges in implementing the ureolysis mechanism in self-healing concrete are discussed and highlighted. In addition, critical discussions and insights regarding the self-healing concrete that utilizes ureolysis are also presented. According to the review, the mechanical strength and microstructure of the bio-concrete utilizing ureolysis mechanism are enhanced while the permeability decreases which thus increases the durability of the concrete. However, the high initial cost, low acceptance of construction workers, and ammonium ions produced during the ureolysis process are barriers that needs to be overcome before the real implementation of ureolytic bacterial concrete on a large commercial scale in the construction industry. Graphical Abstract: (Figure presented.) © The Author(s), under exclusive licence to Shiraz University 2024.