Chemo-mechanics of cemented granular solids subjected to precipitation and dissolution of mineral species

Giuseppe Buscarnera, Arghya Das*

*Corresponding author for this work

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

This paper studies the chemo-mechanics of cemented granular solids in the context of continuum thermodynamics for fluid-saturated porous media. For this purpose, an existing constitutive model formulated in the frame of the Breakage Mechanics theory is augmented to cope with reactive processes. Chemical state variables accounting for the reactions between the solid constituents and the solutes in the pore fluid are introduced to enrich the interactions among the microstructural units simulated by the model (i.e., grains and cement bonds). Two different reactive processes are studied (i.e., grain dissolution and cement precipitation), using the chemical variables to describe the progression of the reactions and track changes in the size of grains and bonds. Finally, a homogenization strategy is used to derive the energy potentials of the solid mixture, adopting probability density functions that depend on both mechanical and chemical indices. It is shown that the connection between the statistics of the micro-scale attributes and the continuum properties of the solid enables the mathematical capture of numerous mechanical effects of lithification and chemical deterioration, such as changes in stiffness, expansion/contraction of the elastic domain, and development of inelastic strains during reaction. In particular, the model offers an interpretation of the plastic strains generated by aggressive environments, which are here interpreted as an outcome of chemically driven debonding and comminution. As a result, the model explains widely observed macroscopic signatures of geomaterial degradation by reconciling the energetics of the deformation/reaction processes with the evolving geometry of the microstructural attributes.

Original languageEnglish (US)
Pages (from-to)1295-1320
Number of pages26
JournalInternational Journal for Numerical and Analytical Methods in Geomechanics
Volume40
Issue number9
DOIs
StatePublished - Jun 25 2016

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Keywords

  • Cement damage
  • Cemented granular materials
  • Chemo-mechanics
  • Constitutive model
  • Dissolution and precipitation
  • Grain breakage

ASJC Scopus subject areas

  • Computational Mechanics
  • Materials Science(all)
  • Geotechnical Engineering and Engineering Geology
  • Mechanics of Materials

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