AI-MONITORED BIO-CEMENTATION FOR SELF-HEALING IN 3D PRINTED CONCRETE

Abstract

The construction industry worldwide is under unprecedented pressure to create sustainable infrastructure that can autonomously self-repair and real-time health-monitor. Approximately 7% of CO2 emissions are generated in the making of concrete structures, which inevitably develop microcracks that impair durability and structural integrity. Traditional methods of cracking repair, such as grouting, epoxy-injection, and manual repairing, are time-consuming, expensive, and harmful to the environment. To overcome these drawbacks, bio-cementation-based self-healing concrete with the mechanism of microbially induced calcium carbonate precipitation (MICP) has become a novel sustainable solution. This bio-precipitation technique using bacterial strains such as Bacillus cereus, Bacillus megaterium, and Bacillus licheniformis has the capacity of self-healing of concrete up to 0.97 mm with 14–32% mechanical strength improvement. Not only does this biological mineralization help to restore structural integrity, it also has a massive impact on increasing of the durability and resistance to chemical attack. However, to fully realize the potential of MICP future challenges such as viability of bacteria in alkaline conditions, nutrient optimization and scaling should be overcome. Emerging technologies such as three-dimensional concrete printing (3DCP), artificial intelligence for crack detection, and smart sensing offer novel possibilities for conducting real-time structural health monitoring (SHM), an important factor in predictive management. This review aims to summarize existing knowledge about bio-cement 3DCP, including: MICP mechanisms and bacterial encapsulation strategies; bio-cement 3DCP materials design and sustainability; AI monitored SHM systems and integrated system performance and future commercialization. This broad review of 20+ primary sources sets a critical framework between microbial self-healing, digital manufacturing and intelligent monitoring. As the evidence shows, bio-cemented 3D-printed concrete can have a compressive strength of more than 50 MPa and it can offer up to 48% reduction of Embodied Carbon as well as ensuring the capacity of autonomous damage detection and repair.