Bio-Based Crack Solution: Utilizing Bacillus Megaterium for Concrete Crack Treatment

Abstract

Concrete cracking poses a major challenge to the longevity and safety of structures, with conventional repair methods often falling short in providing durable, long-term solutions. This study explores an innovative, bio-based approach using Bacillus megaterium for microbial-induced calcite precipitation (MICP) to heal cracks in aging concrete. The method integrates sodium alginate, Bacillus megaterium, urea, and calcium acetate to enhance calcite formation. Experimental results demonstrated a notable improvement in both mechanical strength and durability. Compressive strength increased by 31.83% (from 5.97 MPa to 7.87 MPa), while flexural strength rose by 37.08% (from 0.89 MPa to 1.22 MPa), restoring 78.15% and 73.49% of their original strengths, respectively. Water absorption was significantly reduced by 64.86% (from 6.29% to 2.21%) compared to untreated cracked samples, making the treated concrete more resistant to moisture than even pristine concrete. Statistical analysis confirmed a significant increase in compressive strength (p = 0.012), while improvements in flexural strength (p = 0.069) and water resistance (p = 0.052) showed strong trends toward significance. Over 14 days, visual inspections revealed gradual crack sealing, and scanning electron microscopy (SEM) confirmed dense calcite formations bridging the cracks, reinforcing both mechanical strength and chemical stability. These findings highlight the potential of Bacillus megaterium-based treatment as a viable and eco-friendly alternative for concrete repair. By integrating biotechnology into construction, this method not only extends infrastructure lifespan but also aligns with the global push for sustainable, cost-effective engineering solutions. The improved durability and resilience of treated concrete can enhance structural safety, particularly in disaster-prone and resource-limited regions. This study underscores the growing role of bio-based innovations in creating more sustainable and resilient infrastructure for modern societies.