A comprehensive review of self-healing technology for cementitious materials: Mechanisms, influencing factors, and healing performance

Concrete materials are prone to microcracks throughout the preparation and service process due to inherent properties and the involvement of the external environment, posing threats to durability and safety. Self-healing technology for cementitious materials has gained popularity in recent years, bringing benefits to cure microcracks proactively, control maintenance costs reasonably, and achieve the sustainable development successfully. With a comprehensive summary of the types of self-healing cementitious materials, this paper focuses on four typical technologies (including fibers, mineral admixtures, bacteria, and superabsorbent polymer). The associated healing mechanisms and factors influencing the healing result are described, and the benefits and drawbacks of each of these approaches are evaluated. Meanwhile, the synergistic effects of compounding diverse materials are discussed in this work. Compared to a single material, "multi-material composite modification" can effectively improve the former system's mechanical properties of insufficient self-healing ability, as well as other issues, and is currently one of the critical directions. However, engineering applications of self-healing cementitious materials are in the preliminary stage, with most research remaining theoretical and experimental. Furthermore, a rigorous analysis of the feasibility and effectiveness of chemical doping modification is essential. Expenses should be controlled while achieving eco-friendly targets and streamlining the preparatory process. • Different self-healing technologies for cementitious materials are comprehensively summarized and compared. • Multi-material composite modification is beneficial to concrete mechanical properties. • Synergistically improves limited healing ability. • Compatibility effectively affects the final self-healing results. • Applying self-healing technology is an environmentally friendly and low-carbon solution.