16. Effect of desaturation and temperature on concretes

Title: 16. Effect of desaturation and temperature on concretes
Author(s): F. Brue, N. Burlion, F. Skoczylas, X. Bourbon, G. Camps
Paper category : conference
Book title: NUCPERF 2009 - Long Term Performance of Cementitious Barriers and Reinforced Concrete in Nuclear Power Plants and Waste Management
Editor(s): V. L'Hostis, R. Gens, C. Gallé
Print-ISBN: 978-2-35158-072-1
e-ISBN: 978-2-35158-087-5
Publisher: RILEM Publications SARL
Publication year: 2009
Pages: 143 - 150
Total Pages: 8
Nb references: 8
Language: English

Abstract: In France the proposed repository for high and medium level/long lived nuclear waste consists of a network of underground concrete tunnels in deep geological media. Within the French Agency for Nuclear Waste Management (Andra) concepts this repository will be built in a clay rock (Callovo-Oxfordian layer) at around 500 meters depth.

Many loadings will occur during the whole structure life and among these Desaturation/Resaturation processes (D/R) due to changes in temperature and pore pressure are crucial.

D/R processes are related to relative humidity changes linked with temperature variations.

As D/R lead to shrinkage or swelling strains that often induce micro cracking. These are susceptible to changes in material permeability and mechanical behaviour. This is specifically studied on two different concretes, based on CEM I or CEM V cement, which were selected by Andra. The influence of temperature and cement composition on desiccation shrinkage is shown to be important. Cement composition influences porosity distribution. Therefore transport properties are dependent on cement composition. An increase of temperature accelerates desiccation mechanisms by means of thermal diffusion.

Online publication: 2009-11-16
Publication type : full_text
Public price (Euros): 0.00