A review of fibre reinforced bacterial concrete

Fibre-Reinforced Bacterial Concrete (FRBC) has emerged as a promising sustainable material that integrates fibre-induced crack control with biologically driven self-healing through microbially induced calcium carbonate precipitation (MICP). Fibres such as polypropylene, basalt, glass, steel, and plant-based alternatives enhance ductility, tensile resistance, and crack limitation, while bacterial species including Bacillus subtilis and Sporosarcina pasteurii enable autonomous healing of microcracks up to approximately 0.5 mm. Compared with fibre-only or bacteria-only systems, FRBC demonstrates improved compressive and flexural strengths (5–25%), reduced chloride ingress, enhanced freeze–thaw durability, and healing efficiencies exceeding 70%. This review critically synthesizes recent advances (2010–2025) in FRBC by integrating mechanistic insights, experimental performance trends, and durability behaviour within a unified framework. Beyond conventional crack-closure assessment, emphasis is placed on transport recovery, durability performance, and fibre–bacteria synergy under varying crack and environmental conditions. Despite demonstrated benefits, large-scale application remains constrained by bacterial survivability in alkaline matrices, nutrient depletion, fibre durability, encapsulation cost, and the lack of standardised testing and design guidelines. Key research gaps are identified in long-term multi-exposure durability, optimisation of hybrid fibre–bacteria systems, predictive modelling, and field-scale validation. The review highlights that, while FRBC demonstrates strong potential for enhancing structural resilience and sustainability, its transition from laboratory-scale innovation to practical infrastructure application requires further standardisation, performance validation, and techno-economic assessment.