Ureolytic bacteria-assisted recycling of waste concrete fines

• Published in: Powder technology 2024-02, Vol.434, p.119310, Article 119310
• Main Authors: Holeček, P., Kliková, K., Koňáková, D., Stiborová, H., Nežerka, V.
• Format: Article
• Language: English
• Subjects: Bacteria; Calcite; Concrete recycling; MICP; Ureolysis; Waste concrete fines
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2023.119310

This study investigates the potential of microbially-induced calcite precipitation (MICP) in converting waste concrete fines (WCF), an underutilized byproduct generated during the crushing of old concrete, into construction material. WCF samples treated with Sporosarcina pasteurii DSM 33 for periods ranging from 14 to 90 days exhibited up to an 11% increase in CaCO3 content, compared to a control group treated with a saline solution. The formation of CaCO3 crystals also resulted in a 15% reduction in porosity and, most importantly, enhanced the integrity of the WCF conglomerates, reaching 20% of the stiffness of autoclaved aerated concrete. These results suggest that MICP could be used for the valorization of WCF, aligning with sustainability and circular economy goals. [Display omitted] •MICP process enhances CaCO3 content in waste concrete fines (WCF).•S. pasteurii DSM 33 accelerates CaCO3 crystallization in WCF.•MICP treatment modifies porosity, suggesting improved durability.•Long-term MICP treatment increases mechanical strength of WCF conglomerates.•MICP presents a promising potential for sustainable use of waste concrete.