Bio-Induced Enhancement of Strength and Durability in M30 Grade Concrete Using Sporosarcina pasteurii

The growing deterioration of concrete structures due to microcracks, permeability, and environmental exposure has underscored the need for sustainable and self-healing materials that can extend the service life of infrastructure. Among emerging solutions, bacterial concrete—a bio-based self-healing material—has gained prominence for its ability to autonomously seal cracks through microbial activity. This study investigates the mechanical and durability enhancement of M30 grade concrete using Sporosarcina pasteurii, a ureolytic bacterium capable of inducing calcium carbonate precipitation via the Microbially Induced Calcite Precipitation (MICP) process. In this work, a bacterial culture with a concentration of 10⁶ cells/ml was incorporated into the concrete mix by replacing 10% of the mixing water with a nutrient-enriched bacterial solution. The specimens were evaluated for compressive strength, split tensile strength, and permeability at 7, 14, and 28 days of curing. Experimental results demonstrated significant improvements in compressive and tensile strength, accompanied by a marked reduction in water absorption and permeability relative to conventional concrete. The enhanced performance is attributed to the bio-precipitation of calcite within microcracks and pores, leading to improved matrix densification and reduced pore connectivity