CELL-FREE BIO-CEMENTATION FOR SOILS

Author(s): Dimitrios Terzis and Laloui Lyesse
Paper category: Proceedings
Book title: Proceedings of the Final Conference of RILEM 253-MCI Microorganisms-Cementitious Materials Interactions Volume II
Editor(s): Alexandra Bertron and Henk Jonkers
ISBN: 978-2-35158-207-7 (Set)
ISBN: 978-2-35158-210-7 (Volume 2)
e-ISBN: 978-2-35158-206-0
Publisher: RILEM Publications SARL
Publication year: 2018
Pages: 589-590
Total Pages: 308
Language : English

Abstract: We introduce the application of microbial-induced calcite (CaCO3) precipitation (MICP) via the ureolytic soil bacterium Sporosarcina Pasteurii in freeze-dried form, as a means of enhancing overall MICP efficiency and reproducibility for geotechnical engineering applications. We show that the execution of urea hydrolysis and CaCO3 precipitation persist as a “cell-free” mechanism upon the complete breakdown of rehydrated cell clusters. Further, strength and stiffness parameters of bio-cemented sands are determined. Bio-cemented sands yield compressive strengths up to 12 MPa. We further apply a new methodology towards quantifying crucial microscopic characteristics such as the sizes of CaCO3 particles composing the crystalline bond lattice, the bond-grain contacts and particle orientations. Bonds are found to exhibit distinctive geometries and morphologies when MICP applies to different base materials. We thus contribute to the debate on the importance of factors affecting: (i) MICP efficiency, (ii) the mechanical response of bio-cemented sand and (iii) its peculiar micro- architecture.

Online publication : 2018
Publication type : full_text
Public price (Euros) : 0.00