Multi-scale modeling to predict ion diffusivity of cracked cement-based materials

Title: Multi-scale modeling to predict ion diffusivity of cracked cement-based materials
Author(s): Fabrice Bernard, Siham Kamali-Bernard
Paper category : conference
Book title: 2nd International Symposium on Service Life Design for Infrastructures
Editor(s): K. van Breugel, Guang Ye, Yong Yuan
Print-ISBN: 978-2-35158-096-7
e-ISBN: 978-2-35158-097-4
Publisher: RILEM Publications SARL
Publication year: 2010
Pages: 157 - 166
Total Pages: 10
Nb references: 13
Language: English

Abstract: In durability based design, diffusivity of ions through cement-based materials is one of the most important factors that determine the service life of concrete structures. This one can be severely reduced by the presence of cracks, whatever is their cause: early age, thermal loading, shrinkage...
In this work, the relationship between load inducing cracking and mortar diffusivity is studied by means of the MuMoCC platform (Multi-scale Modelling of Computational Concrete). First, the methodology adopted to model the mechanical behaviour of mortar subjected to a tensile or compressive test is presented. The heterogeneous nature of the material is taken into account at both the micro (cement paste) and the meso (mortar) levels.
Two numerical tools are used and coupled: the hydration model CEMHYD3D and the finite element software ABAQUS. This methodology allows reproducing successfully the stress-strain curves of the material as well as crack patterns due to this mechanical overloading.
Then, the well-known HTO diffusion test is simulated on both sound and cracked materials in order to derive the effective diffusion coefficient of the heterogeneous materials. That allows obtaining the increase of this parameter for various effort levels corresponding to different points in the tensile or the compressive stress-strain curves. The modelling results are successfully validated by comparison to experimental data found in the literature.

Online publication: 2011-04-20
Publication type : full_text
Public price (Euros): 0.00