State-of-the-Art Review of Biomineralization-Based Self-Healing Concrete: Chronological Development from Bacteria to Fungi and Algae

Cracks pose a significant threat to the structural integrity, durability, and service life of concrete; therefore, sustainable, autonomous repair solutions are paramount. In the last 25 years, bio-based self-healing, particularly microbially induced calcium carbonate precipitation (MICP), has become an attractive technology. Self-healing by bacteria has been studied extensively, but the use of other biomineralization agents, such as fungi and algae, has unique benefits, namely, hyphal crack-bridging and photosynthetic mineralization. In this paper, a thorough state-of-the-art review is presented that compares bacteria, fungi, and algae as biomineralization agents. The comparative methodology involves a structured review of the peer-reviewed literature on these agents (2000–2025), and compares them on a set of common performance criteria: (i) biochemical precipitation mechanisms (ureolytic, non-ureolytic, photosynthetic and hyphal bridging); (ii) quantitative crack-healing efficiency (maximum width of crack closed); (iii) mechanical performance recovery (restoration of compressive and tensile strength); (iv) long-term durability enhancement. Moreover, it critically evaluates implementation challenges, including biological viability in extreme cementitious media, encapsulation methods, and the levels of technological maturity for practical engineering applications. The findings of this synthesis outline key research gaps and offer a roadmap for creating hybrid, consortium-based self-healing systems to help engineers and researchers select the best bio-based concrete for a given structure and environment.