Sustainable Concrete Restoration Using Microbial-Induced Carbonate Precipitation Technology: Insights from Laboratory and Field Applications

Concrete structures are vulnerable to cracking from mechanical, chemical, and environmental stresses, which compromise durability and increase maintenance costs. Conventional repair methods, such as epoxy injection and cementitious grouting, often depend on non-renewable materials and contribute to environmental waste. This study explores Microbially Induced Calcium Carbonate Precipitation (MICP) using Sporosarcina pasteurii as a sustainable approach for repairing cracks in cement-based materials. Laboratory experiments were conducted on mortar samples with 1.0 mm predefined cracks, while in-situ trials were performed on cracked cement surfaces at UTMSPACE. Treated samples recovered up to 88.1% of their original tensile strength (19.59 kN compared to 22.24 kN for controls), confirming the structural reinforcement potential of MICP. SEM–EDX analysis showed uniform calcium carbonate deposition along the crack surfaces, while FTIR spectroscopy confirmed biomolecular signatures linked to calcite formation. Water absorption tests revealed a significant reduction in permeability, with secondary absorption rates decreasing from 0.0206 mm/√s to 0.0009 mm/√s, indicating enhanced durability. Field application validated the practicality of the method, achieving visible crack sealing and mineral deposition within one working day per treated area. These results highlight MICP as a viable, eco-friendly alternative to conventional repair strategies, offering both mechanical and environmental benefits. The findings support the integration of MICP into sustainable infrastructure maintenance practices.