Smart Bio-Agents-Activated Sustainable Self-Healing Cementitious Materials: An All-Inclusive Overview on Progress, Benefits and Challenges

Cementitious materials deteriorate progressively with the formation of cracks that occur due to diverse physical, chemical, thermal, and biological processes. Numerous strategies have been adopted to obtain cement-based self-healing materials and determine the novel self-healing mechanisms. The uses of microbes have been established to improve the thickness of the healed crack and mechanical properties of the concrete, a phenomenon seldom addressed in the literature. Based on these factors, this article comprehensively appraises the smart bio-agents-based autonomous healing performance of concrete to demonstrate the recent progress, expected benefits, and ongoing challenges. The fundamentals, design strategies, and efficacy of the smart bio-agents-activated self-healing cementitious materials are the recurring themes of this overview. Furthermore, the effects of various processing parameters on the performance of cementitious self-healing smart bio-agents are discussed in-depth. The achievements, knowledge gaps, and needs for future research in this ever-evolving area for the sustainability and resilience of the built environment are highlighted.