Enhancing microbial self-healing of cementitious materials using natural fibre-based carriers

Abstract

Cracks in cement-based materials pose a significant threat to long-term durability and service life, especially under harsh environmental exposure. To address this, bacteria-based self-healing systems have been developed, leveraging microbial-induced calcium carbonate precipitation (MICP) to autonomously repair cracks. However, achieving effective healing particularly in wider cracks requires the use of suitable carrier materials that protect bacterial viability and facilitate consistent calcium carbonate deposition. This thesis investigates the role of different carrier types in enhancing self-healing efficiency. Three carriers -jute fibre, flax fibre, and expanded perlite aggregate (EPA)—were systematically evaluated for their ability to serve as bacterial protective carrier in mortar, focusing on their influence on crack closure, water permeability, and mechanical performance under practical conditions.