Characterization of microstructural and physical properties changes in biocemented sand using 3D X-ray microtomography

Dadda, Abdelali; Geindreau, Christian; Emeriault, Fabrice; Roscoat, Sabine Rolland Du; Garandet, Aurélie; Sapin, L.; Filet, Annette Esnault

doi:10.1007/s11440-017-0578-5

Cited by 67 publications

(43 citation statements)

References 24 publications

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“…For example, the 2BT subsample has shown very similar results in the 3D space directions (Young modulus: E 1 = 29 GPa, E 2 = 29 GPa, and E 3 = 25 GPa). This result is consistent with the ones obtained for the microstructure and other physical properties (effective diffusion tensor, permeability) . According to these results, the computed effective elastic properties reduce to the mean Young modulus ( E eff = ( E 1 + E 2 + E 3) / 3) and mean shear modulus.…”

Section: Methodssupporting

confidence: 90%

“…A resolution of 0.65 μm/pixel is chosen in order to visualize the calcite crystals which have a small size (15 to 20 μm). Each 3D image in gray level (image a, Figure ) is treated in order to separate the three phases (sand grains, calcite, and pores) (image b, Figure ) . A 3D watershed algorithm implemented in Visilog is then used in order to separate the grains.…”

Section: Methodsmentioning

confidence: 99%

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Influence of the microstructural properties of biocemented sand on its mechanical behavior

Dadda

Geindreau

Emeriault

et al. 2018

Num Anal Meth Geomechanics

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Summary The mechanical efficiency of the biocementation process is directly related to the microstructural properties of the biocemented sand, such as the volume fraction of calcite, its distribution within the pore space, coordination number, contact surface area, and types of contact. In the present work, some of these microscopic properties are computed, from 3D images obtained by X‐ray tomography of biocemented sand. These properties are then used as an input in current analytical models to estimate the elastic properties (Young and shear moduli) and the strength properties (Coulomb cohesion). For the elastic properties, the analytical estimates (contact cement theory model) are compared with classical bounds, self‐consistent estimate and numerical results obtained by direct computation (FEM computation) on the same 3D images. Concerning the cohesion, an analytical model initially developed to estimate the cohesion due to suction in unsaturated soils is modified to evaluate the macroscopic cohesion of biocemented sands. Such analytical model is calibrated on experimental data obtained from triaxial tests performed on the same biocemented sand. In overall, the presented results point out the important role of some microstructural parameters, notably those related to the contact, on such effective parameters.

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Section: Methodssupporting

confidence: 90%

Section: Methodsmentioning

confidence: 99%

Influence of the microstructural properties of biocemented sand on its mechanical behavior

Dadda

Geindreau

Emeriault

et al. 2018

Num Anal Meth Geomechanics

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“…Figure shows the normalized permeability ( K / K o ) with the pore volume fraction of carbonate ( S cc ) and with the porosity normalized to the baseline value ( ϕ / ϕ o ), superimposed with the analytical models and some previously published data (Armstrong & Ajo‐Franklin, ; Dadda et al, ). The permeability was substantially reduced as the carbonate minerals precipitated within the sand pack.…”

Section: Discussionmentioning

confidence: 98%

“…On this basis, various attempts have been made to understand natural carbonate precipitation processes (e.g., Castanier et al, ; Drew, ; Krumbein, , ) and their effects on various sediment properties. Studies have focused mostly on mechanical strength (e.g., Akili & Torrance, ; DeJong et al, ; Ismail et al, ; Kucharski et al, ; Molenaar & Venmans, ; Whiffin et al, ) and permeability (e.g., Cheng et al, ; Dadda et al, ; Ferris et al, ; Nemati & Voordouw, ).…”

Section: Introductionmentioning

confidence: 99%

X‐Ray Computed Microtomography Imaging of Abiotic Carbonate Precipitation in Porous Media From a Supersaturated Solution: Insights Into Effect of CO₂ Mineral Trapping on Permeability

Baek

Hong

Kim

et al. 2019

Water Resources Research

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Abiotic carbonate precipitation has garnered significant interest as a mechanism for mineral trapping of carbon dioxide (CO2) in geologic carbon storage, as a natural diagenetic process frequently occurring in marine environments, and as an engineering approach for soil improvement. This study explored pore‐scale precipitation of calcium carbonate (CaCO3) and its effect on the permeability of porous media, using X‐ray computed microtomography (CMT). In a column experiment, CaCO3 was precipitated in a sand pack from a supersaturated CaCO3 solution, while porosity, pore volume fraction of carbonate, and permeability were being monitored and X‐ray CMT images were being acquired. Permeability reduction by ~99.94% was observed when precipitated carbonate occupied ~46–47% of pore volume. The X‐ray CMT images showed that carbonate crystals were initially nucleated onto sand grain surfaces, which facilitated subsequent precipitation, indicating a predominantly grain‐coating behavior. The scanning electron microscopy revealed the carbonate crystals of ~1–20 μm in size and the presence of internal pores in the carbonate layers at the submicrometer scale. Variations in carbonate layer thickness and geometric tortuosity, and preferential carbonate precipitation behavior with local clogging were examined through morphological analysis and phase segmentation. Particularly, the pore‐scale precipitation pattern and hence the pore geometry were found to evolve with continued precipitation from a grain‐coating behavior, through a pore‐filling behavior, and finally into a dramatic pore‐throat‐clogging behavior. Our results provide unique experiment data for predictive modeling of long‐term CO2 transport and provide new insights into the changes in physical and transport properties during CO2 mineral trapping.

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“…The resulting precipitates then form inter-particle cementation between coarse soil particles [29,30,57,85]. The MICP method has been widely explored in efforts to enhance the inter-particle cementation, which results in significant cohesion enhancement [23,27,53,59] and hydraulic conductivity control [24,28] of sandy or silty soils. Meanwhile, different approaches using microbial excretions (e.g., biopolymers) as a binder material for various soil treatment purposes are now being actively investigated [13, 16-18, 45, 66].…”

Section: Introductionmentioning

confidence: 99%

Shear strength behavior and parameters of microbial gellan gum-treated soils: from sand to clay

2018

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Microbial biopolymers have recently been introduced as a new material for soil treatment and improvement. Biopolymers provide significant strengthening to soil, even in small quantities (i.e., at 1/10th or less of the required amount of conventional binders, such as cement). In particular, thermo-gelating biopolymers, including agar gum, gellan gum, and xanthan gum, are known to strengthen soils noticeably, even under water-saturated conditions. However, an explicitly detailed examination of the microscopic interactions and strengthening characteristics between gellan gum and soil particles has not yet been performed. In this study, a series of laboratory experiments were performed to evaluate the effect of soil-gellan gum interactions on the strengthening behavior of gellan gum-treated soil mixtures (from sand to clay). The experimental results showed that the strengths of sand-clay mixtures were effectively increased by gellan gum treatment over those of pure sand or clay. The strengthening behavior is attributed to the conglomeration of fine particles as well as to the interconnection of fine and coarse particles, by gellan gum. Gellan gum treatment significantly improved not only interparticle cohesion but also the friction angle of clay-containing soils.

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Characterization of microstructural and physical properties changes in biocemented sand using 3D X-ray microtomography

Cited by 67 publications

References 24 publications

Influence of the microstructural properties of biocemented sand on its mechanical behavior

Influence of the microstructural properties of biocemented sand on its mechanical behavior

X‐Ray Computed Microtomography Imaging of Abiotic Carbonate Precipitation in Porous Media From a Supersaturated Solution: Insights Into Effect of CO₂ Mineral Trapping on Permeability

Shear strength behavior and parameters of microbial gellan gum-treated soils: from sand to clay

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Characterization of microstructural and physical properties changes in biocemented sand using 3D X-ray microtomography

Cited by 67 publications

References 24 publications

Influence of the microstructural properties of biocemented sand on its mechanical behavior

Influence of the microstructural properties of biocemented sand on its mechanical behavior

X‐Ray Computed Microtomography Imaging of Abiotic Carbonate Precipitation in Porous Media From a Supersaturated Solution: Insights Into Effect of CO2 Mineral Trapping on Permeability

Shear strength behavior and parameters of microbial gellan gum-treated soils: from sand to clay

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X‐Ray Computed Microtomography Imaging of Abiotic Carbonate Precipitation in Porous Media From a Supersaturated Solution: Insights Into Effect of CO₂ Mineral Trapping on Permeability