Abstract
Bio-cement, based on microbial-induced mineralization, can consolidate the loose particles and be applied to foundation reinforcement, dust control, desert settlement, repair cementitious materials crack, and other fields. In the paper, two kinds of bio-cement, such as bio-carbonate cement and bio-phosphate cement, were discussed as novel binders. The calcium carbonate (calcite), induced precipitation via Sporosarcina pasteurii, could cement between loose sandy soil particles. A series of sand-cemented experiments were conducted to confirm the cemented properties, and a numerical model based on the distribution of the concentration of Sporosarcina pasteurii was established to further analyze bio-grouting process. The evolution law of microstructure was revealed by X-ray computed tomography (X-CT) technique. The atomic binding energy of C-O bond in calcium carbonate, Si-O bond and Si in sand analysis showed that microbial-induced calcium carbonate interacted with surface of loose sand particles formed the intermolecular hydrogen bond. The other kind of bacteria (Bacillus subtilis) could hydrolyze organic phosphate monoester and released PO43-, which could react with different metal cations formed bio-phosphate minerals. The bio-phosphate cement can be used as treatment of sandy soil foundation, functional materials, remediation of heavy metals in contaminated soil, and so on.
Highlights
Biological mineralization as a common phenomenon in nature is a process of solid phases of various materials with special advanced structures assembled in biological systems
As early as 1992, microbiallyinduced carbonate precipitation has been put forward to reduce the porosity of highly permeable structures, and the US patent was released through Ferris et al.[1]
Bio-carbonate cement has been developed to apply in cementation field by several research groups, of which the main institutes are Murdoch University (Australia),[5,7] Delft university of technology (Netherlands),[8,9] Southeast University (China),[10,11] University of California (USA),[12,13] and so on
Summary
Biological mineralization as a common phenomenon in nature is a process of solid phases of various materials with special advanced structures assembled in biological systems. With the participation of the microbe, calcium carbonate precipitation can occur, and this process is generally considered to be microbial-induced mineralization. Qian et al started to carry out the relative research of bio-cement in 2004, and got first patent in China.[6] In recent years, bio-carbonate cement has been developed to apply in cementation field by several research groups, of which the main institutes are Murdoch University (Australia),[5,7] Delft university of technology (Netherlands),[8,9] Southeast University (China),[10,11] University of California (USA),[12,13] and so on. Bio-cement can be prepared by microbial-induced mineral precipitation and bind loose sand particles into a bio-sandstone. The cementation essence of bio-cement, evolution law of microstructure, property of bio-sandstones, and potential application will be discussed according to Qian et al in recent years
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
