MULTI-SCALE MODELING OF THE EVOLUTION OF THE TRANSPORT PROPERTIES OF CEMENT PASTES SUBJECT TO LEACHING AND CARBONATION

Author(s): N. Seigneur , A. Dubus, P.E. Labeau, V. Detilleux, O. Destin and A. Dauzères
Book Title: RILEM International Symposium on Concrete Modelling - CONMOD 2014
Editor: Kefei Li, Peiyu Yan and Rongwei Yang
ISBN: 978-2-35158-139-1
e-ISBN: 978-2-35158-140-7
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 367-373
Total Pages: 7
Language: English

Abstract: The long-term management of radioactive waste is a very broad field of research from which rise different problems and uncertainties. In many of international projects, concrete constitutes one of the main barrier against the migration of the radionuclides towards the biosphere. Under the repository conditions, the cementitious materials will encounter physicochemical attacks, notably from the infiltrating water. This will have an impact on their microstructures and transport properties, potentially compromising their safety functions. To assess the performances of the cementitious materials, reactive transport codes (such as Hytec) are used. Those models use Archie’s empirical law to model the feedback of porosity changes on the transport properties. However, Archie’s law is inappropriate for cementitious materials, which exhibit a pretty unique pore structure extending from the nanopores of the Calcium Silicate Hydrates (C-S-H) gel to the micrometric capillary pores. In order to obtain a better general feedback relation applicable to cementitious materials, an intensive series of dedicated experiments focused on the leaching and the carbonation of pure C-S-H and of mixtures of C-S-H with Portlandite are currently in progress. The experimental campaign is described. Some preliminary results are also presented, consisting of Monte Carlo and homogenization simulations.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00