Periodic Reporting for period 4 - BIOGEOS (Bio-mediated Geo-material Strengthening for engineering applications)
Periodo di rendicontazione: 2023-05-01 al 2024-04-30
a) Microscale studies involve real-time observation of biocementation initiation and evolution using video microscopy on microfluidic devices, coupled with image processing algorithms.
Relevant publication: Elmaloglou, A., Terzis, D., De Anna, P. and Laloui, L., 2022. Microfluidic study in a meter-long reactive path reveals how the medium’s structural heterogeneity shapes MICP-induced biocementation. Scientific Reports, 12(1), p.19553.
https://www.nature.com/articles/s41598-022-24124-6
b) Application and quality assessment/control of biocementation at the scale of real geotechnical works, including novel approaches like ex-situ hydrolysis to eventually treat residual ammonium which commonly represents a bottleneck in traditional biocementation applications.
Relevant publication: Harran, R., Terzis, D. and Laloui, L., 2023. Addressing the challenges of homogeneity, quality control and waste handling in soil bio-cementation: a large-scale experiment. Soils and Foundations, 63(4), p.101332.
https://www.sciencedirect.com/science/article/pii/S0038080623000616
c) Characterization of the porous matrix using advanced computed microtomography tools.
Relevant publication: Roy, N., Frost, J.D. and Terzis, D., 2023. 3-D contact and pore network analysis of MICP cemented sands. Granular Matter, 25(4), p.62.
https://link.springer.com/article/10.1007/s10035-023-01347-6
d) The establishment of a bio-chemo-hydro-mechanical model of transport, strength and deformation for bio-cementation applications which can easily be calibrated with existing experimental results. The model application is demonstrated through the case of a 2D shallow foundation strengthening via biocementation.
Relevant publication: Bosch, J.A. Terzis, D. and Laloui, L., 2024. A bio-chemo-hydro-mechanical model of transport, strength and deformation for bio-cementation applications. Acta Geotechnica, pp.1-17.
https://link.springer.com/article/10.1007/s11440-023-02172-0
e) Investigations into the influence of applied direct currents on biocementation processes, including extensive crystalline characterization analysis.
Relevant publication: Terzis, D., Hicher, P. and Laloui, L., 2020. Direct currents stimulate carbonate mineralization for soil improvement under various chemical conditions. Scientific Reports, 10(1), p.17014.
https://www.nature.com/articles/s41598-020-73926-z
f) Development of a novel system for producing biocementation agents in the form of microcapsules activated under controlled environments.
Relevant publication: Saracho, A.C. Lucherini, L., Hirsch, M., Peter, H.M. Terzis, D., Amstad, E. and Laloui, L., 2021. Controlling the calcium carbonate microstructure of engineered living building materials. Journal of Materials Chemistry A, 9(43), pp.24438-24451.
https://pubs.rsc.org/en/content/articlehtml/2021/ta/d1ta03990c
The project's adoption of a multiphysical and multiscale approach has played a key role in maturing the technology and propelling its future integration prospects. Main questions addressed during the project include the spatiotemporal evolution of biocementation, the influence of varying pore space properties on the precipitated matrix outcome, the application and monitoring of biocementation at large scales, mitigation strategies for residual ammonium waste, and the utilization of numerical tools to simulate future biocementation applications.
By providing answers to these critical questions and insights into previously unexplored physical mechanisms, the scientific output of the project has established a new foundation for the future of bio-geotechnical engineering. The knowledge gained from BIOGEOS sets the stage for further advancements in sustainable infrastructure development and environmental remediation through the innovative application of biocementation technology.
[1] Harran, R., Terzis, D. and Laloui, L., 2023. Mechanics, modeling, and upscaling of biocemented soils: a review of breakthroughs and challenges. International Journal of Geomechanics, 23(9), p.03123004.
[2] Terzis, D. and Laloui, L., 2019. A decade of progress and turning points in the understanding of bio-improved soils: A review. Geomechanics for Energy and the Environment, 19, p.100116.