Research progress and application prospects of microbial mineralization for repairing cracks in recycled concrete

Abstract

The accumulation of construction waste imposes a significant burden on the environment. Recycling construction waste into concrete using recycled aggregate has emerged as an effective solution. However, the poor mechanical properties of recycled concrete limit its widespread application. Microbial mineralization-induced calcium carbonate precipitation (MICP) has been proposed as an environmentally friendly repair method to enhance the performance of recycled concrete. Although this technology demonstrates considerable potential, practical applications face several challenges. This paper systematically reviews the key issues in this field and evaluates existing solutions, highlighting their advantages and limitations. The primary challenge is bacterial survival, which has been addressed through two main strategies: (1) enhancing bacterial adaptability via domestication and (2) modifying the external environment by reducing pH and applying protective shells. This dual-protection approach improves bacterial viability and mitigates external environmental interference. The integration of microbial mineralization with recycled concrete is not only environmentally sustainable but also economically advantageous, reducing initial capital investment by 50 % compared to conventional remediation methods while significantly lowering maintenance costs. Additionally, incorporating artificial intelligence into microbial concrete enables real-time monitoring and process optimization, offering an innovative pathway for sustainable construction.