A coupled chemo-thermo-hygro-mechanical model of concrete at high temperature and failure analysis

Xikui Li, Rongtao Li, B. A. Schrefler

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

A hierarchical mathematical model for analyses of coupled chemo-thermo-hygro-mechanical behaviour in concretes at high temperature is presented. The concretes are modelled as unsaturated deforming reactive porous media filled with two immiscible pore fluids, i.e. the gas mixture and the liquid mixture, in immiscible-miscible levels. The thermo-induced desalination process is particularly integrated into the model. The chemical effects of both the desalination and the dehydration processes on the material damage and the degradation of the material strength are taken into account. The mathematical model consists of a set of coupled, partial differential equations governing the mass balance of the dry air, the mass balance of the water species, the mass balance of the matrix components dissolved in the liquid phases, the enthalpy (energy) balance and momentum balance of the whole medium mixture. The governing equations, the state equations for the model and the constitutive laws used in the model are given. A mixed weak form for the finite element solution procedure is formulated for the numerical simulation of chemo-thermo-hygro-mechanical behaviours. Special considerations are given to spatial discretization of hyperbolic equation with non-self-adjoint operator nature. Numerical results demonstrate the performance and the effectiveness of the proposed model and its numerical procedure in reproducing coupled chemo-thermo-hygro-mechanical behaviour in concretes subjected to fire and thermal radiation.

Original languageEnglish (US)
Pages (from-to)635-681
Number of pages47
JournalInternational Journal for Numerical and Analytical Methods in Geomechanics
Volume30
Issue number7
DOIs
StatePublished - Jun 1 2006

Keywords

  • Concrete
  • Coupled chemo-thermo-hygro-mechanical processes
  • High temperature
  • Numerical modelling

ASJC Scopus subject areas

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

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