Environmental sustainability assessment of microbial concrete: a comprehensive life cycle analysis

Concrete is widely utilized in construction due to its strength and versatility; however, it is also a major contributor to CO2 emissions and suffers from low tensile strength, often resulting in cracking that degrades the material and reduces the lifespan of concrete structures. Recently, microbial concrete has emerged as an innovative solution to these challenges. Previous research has predominantly focused on the crack-healing capabilities and other beneficial properties of microbial concrete such as enhancement of compressive strength, and reduction in water absorption. However, the environmental sustainability of this material has not been thoroughly investigated. To address this gap, a comprehensive life cycle assessment (LCA) of microbial concrete was conducted by incorporating a spore-forming bacteria, namely, Bacillus subtilis. By establishing a relationship between the w/c ratio, bacterial cell concentration, and compressive strength through response surface methodology (RSM) and by utilizing the generated RSM data at open LCA software, a detailed analysis of the CO2 emissions associated with microbial concrete compared to conventional concrete formulations was conducted. The findings indicate that microbial concrete can significantly reduce CO2 emissions, achieving reductions of up to 21% compared to traditional concrete. This substantial decrease highlights microbial concrete as a more environmentally sustainable alternative in the construction industry. In addition to its environmental benefits, microbial concrete offers enhanced structural resilience due to its self-healing properties.