Reactive Transport in Evolving Porous Media

Seigneur, Nicolas; Mayer, K. Ulrich; Steefel, Carl I.

doi:10.2138/rmg.2019.85.7

Cited by 83 publications

(92 citation statements)

References 240 publications

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“…using a Monod-type inhibition depending on calcite dissolution. Or using an accurate available surface model of the portlandite grains, which would be dependent on calcite volume fractions, similar to what has been described in [76,77,78,67].…”

Section: Thermodynamic Databasementioning

confidence: 99%

Predicting the atmospheric carbonation of cementitious materials using fully coupled two-phase reactive transport modelling

Seigneur

Kangni-Foli

Lagneau

et al. 2020

Cement and Concrete Research

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The durability assessment of cementitious materials and concrete subjected to atmospheric carbonation of concrete has been an extensive study of research. Experimental studies on the subject show, among other results, that the response depends strongly on the cement composition. This paper focuses on two model materials: an hydrated C 3 S paste and a low-pH paste, which exhibits a higher tendency to cracking. We show that a fully coupled reactive transport model can reproduce the measured experimental depths of carbonation without a need of fitting parameters. A sensitivity provides insights about the most relevant parameters to accurately model the atmospheric carbonation. Furthermore, results suggest that low-pH cement materials might be inherently less mechanically robust when subjected to atmospheric carbonation, due to a higher C-S-H decalcification rate. This implies that these materials are more likely to develop fractures, which could have implications in the framework of gas or radioactive waste disposal.

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Section: Thermodynamic Databasementioning

confidence: 99%

Predicting the atmospheric carbonation of cementitious materials using fully coupled two-phase reactive transport modelling

Seigneur

Kangni-Foli

Lagneau

et al. 2020

Cement and Concrete Research

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“…Whereas the evolution of the porosity ϕ in time can easily be deduced from the local mass conservation property of the transport equation (and its discretization for RT 0 / P 0 elements), the specific surface area is a quantity generally not accessible from macroscopic information. As a remedy, the following relation between σ and ϕ is often assumed in three dimensions (Seigneur et al, 2019):

σ = σ_{0} {(\frac{1 - ϕ}{1 - ϕ_{0}})}^{\frac{2}{3}},

with reference surface area σ 0 at ϕ 0 . In our two‐dimensional setup this transfers to

σ = \sqrt{4 π false(1 - ϕ false)}

for circular grains.…”

Section: Simulations Of Hydraulic Parametersmentioning

confidence: 99%

Efficiency and Accuracy of Micro‐Macro Models for Mineral Dissolution

Gärttner

Frolkovič

Knabner

et al. 2020

Water Resources Research

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Micro‐macro models for dissolution processes are derived from detailed pore‐scale models applying upscaling techniques. They consist of flow and transport equations at the scale of the porous medium (macroscale). Both include averaged time‐ and space‐dependent coefficient functions (permeability, porosity, reactive surface, and effective diffusion). These are in turn explicitly computed from the time‐ and space‐dependent geometry of unit cells and by means of auxiliary cell problems defined therein (microscale). The explicit geometric structure is characterized by a level set. For its evolution, information from the transport equations solutions is taken into account (micro‐macro scales). A numerical scheme is introduced, which is capable of evaluating such complex settings. For the level‐set equation a second‐order scheme is applied, which enables us to accurately determine the dynamic reactive surface. Local mesh refinement methods are applied to evaluate Stokes type cell problems using P2/P1 elements and a Uzawa type linear solver. Applications of our permeability solver to scenarios involving static and evolving geometries are presented. Furthermore, macroscopic flow and transport equations are solved applying mixed finite elements. Finally, adaptive strategies to overcome the computational burden are discussed. We apply our approach to the dissolution of an array of dolomite grains in the micro‐macro context and validate our numerical scheme.

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“…The evolution of these properties is in many applications relatively slow compared to flow and transport and the coupling is assumed weak. In some other applications, the feedback processes are significant and are addressed specifically in the chapter devoted to porous media evolution in this volume (Seigneur et al 2019, this volume).…”

Section: Multiscale Aspects Of Process Couplingmentioning

confidence: 99%