Experiment with Adding Materials Like Microcapsules or Bacteria to Concrete for Self-Healing Properties

Concrete is a fundamental material in modern infrastructure, yet its inherent brittleness and tendency to develop microcracks compromise durability and long-term performance. Recent advancements in materials science have led to the development of self-healing concrete, which can autonomously repair cracks and restore structural integrity. This review critically examines two major self-healing approaches: microcapsule-based and bacteria-based systems. Microencapsulation involves embedding synthetic or mineral healing agents in capsules that rupture upon crack formation, providing immediate chemical sealing. Conversely, bacterial systems utilize microorganisms such as Bacillus subtilis or Sporosarcina pasteurii, which precipitate calcium carbonate through microbial induced calcite precipitation (MICP) to seal cracks over time. The paper discusses the underlying healing mechanisms, material compositions, embedding techniques, environmental triggers, and performance indicators of each system. Comparative analysis reveals that while microcapsules offer rapid and targeted healing, bacterial systems provide sustainable, repeatable, and long-lasting crack repair. Despite significant laboratory success, challenges remain in terms of scalability, standardization, cost, and environmental resilience. The review concludes with an exploration of hybrid techniques, smart materials, and future directions for integrating self-healing technologies into sustainable and resilient construction practices.