Sustainable bio-based construction: A review of MICP technology and bio-cementation across scales and materials

The urgent need to minimize construction-related CO 2 emissions and negative environmental impacts to enhance sustainability and economic circularity in the construction sector has led to revolutionary innovations in traditional practices. During the past two decades, microbially induced calcium carbonate precipitation (MICP), an emerging biomineralization technique mediated by bacteria and photosynthetic algae, has emerged as a widely employed bio-based approach in geotechnical and concrete engineering to treat different types of soils, rocks, as well as grout and concrete. A vast amount of research has been carried out to understand the impact of MICP on the behavior of materials and performance of systems in various contexts. However, most reviews focus individually on the geotechnical aspect (e.g., soil properties) or concrete engineering (e.g., self-healing concrete). This review examines recent developments in the application of MICP to treat diverse materials like soils, rocks, and concrete. The comparative analysis demonstrates that MICP can yield significant engineering improvements, such as increasing the unconfined compressive strength (UCS) of loose sands by up to 1.5–3.0 MPa, restoring up to 386 kPa of splitting tensile strength in cracked mortar, and reducing the permeability of fractured rocks by 3 to 4 orders of magnitude. Additionally, quantitative assessments reveal that optimal reagent concentrations (typically ranging from 0.5 M to 1.0 M of urea and calcium sources) play a major role in maximizing precipitation efficiency across these materials. The review also emphasizes that long-term environmental conditions critically affect the durability of bio-cemented structures. While MICP-treated materials exhibit strong resistance to freeze-thaw cycles (retaining 70%–90% of their initial strength after 12 cycles), wet-dry cycles and acid rain exposure can cause up to an 80% reduction in UCS. The inclusion of bio-additives, such as 0.2–0.4% by weight of basalt or jute fibers, has emerged as a vital strategy, reducing weathering-induced mass loss to 10% and enhancing long-term resilience. This study aims to offer a robust foundation for future research aimed at overcoming existing limitations and scaling MICP technologies for commercial implementation in geotechnical and construction engineering.