Study on Self-Healing Concrete Using Bacteria and Polymers: Advancing Autonomous Repair in Civil Infrastructure
Abstract
Background: Concrete structures in underprivileged areas, particularly in Osmanabad, Maharashtra, are prone to early degradation due to cracking, environmental distress, and inadequate, unskilled maintenance. The current mend strategies are passive, labour-heavy, and economically not viable in these situations. On the other hand, recent developments in self-healing technology for self-healing concrete, based on microbial and polymeric agents, give rise to an attractive alternative for extending the service life and service life cycle of structures. Objectives: In this research, the crack-healing effectiveness, durability properties, and practical feasibility of the bacterial self-healing and polymer self-healing were analysed and compared. A context-sensitive methodology was used, ensuring its relevance to the infrastructure issues faced by Osmanabad, such as water shortage, thermal stress, and technical resource constraints. The study aimed at providing practical, user-oriented implications consistent with the principles of the human-centred design approach. Methods: A hybrid approach involving laboratory experimentation and pilot-scale field testing was used. In the bacterial concrete, the strains of Bacillus subtilis were immobilized in polymer-coated lightweight aggregates, and the polymer-based ones, microencapsulated epoxy, were employed. Normal M25 concrete was used as a control. Healing efficiency, compressive strength recovery, and water penetration were monitored by using UPV, SEM, and image analysis over 90 days. Field structures (village tanks, culverts, and toilets) were monitored under real-life conditions. Results: The findings revealed that the bacterial concrete attained 88.9% crack closure and 84.6% decrease in permeability between both the polymer systems for long-term durability. The polymer-based mixes showed very high-healing kinetics, but they presented re-cracking under cyclic loading. The stakeholder perceptions showed overall higher trust and acceptance in the bio-concrete, especially in remote areas with limited interference. Conclusion: In short, autogenic rehabilitation concrete such as biologically inspired mixtures – has great potential to bring sustainable, resilient infrastructure to at-need areas. The research highlights the necessity for co-design of solutions that merge advanced materials with local contexts, and it highlights hybrid systems and digital monitoring as critical areas to advance in future research.