12. Pore structure and transport properties of high-volume fly ash materials used for radioactive waste disposal facilities

Title: 12. Pore structure and transport properties of high-volume fly ash materials used for radioactive waste disposal facilities
Author(s): K. Kinomura, V. Baroghel-Bouny
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: 109 - 117
Total Pages: 9
Nb references: 14
Language: English

Abstract: Specifications for underground disposal facilities for radioactive wastes with multicomplex artificial barriers providing different functions are currently studied in Japan. A specific mortar layer with high content of mineral admixtures is expected to prevent diffusion of nuclide molecules emitted from radioactive wastes in ground water to outer environment.
In general, transport properties of porous media depend not only on the total porosity, but also on the pore size distribution, the connectivity of the pore structure, the formation of hydrated compounds, physicochemical reactions and so on. In this study, various measurements on four different mortar mixtures, varying proportion of fly ash to binder with the same high amount of limestone, have been performed at given ages. They consist of compressive strength, porosity accessible to water and to mercury, electrical resistivity, apparent gas permeability and apparent chloride diffusion coefficient. As a result of comprehensive measurements, it has been quantitatively identified that the remarkable evolution of pore structures occurred, but only after a long period of time due to pozzolanic reactions, depending on the fly ash content. Consequently, the transport properties measured on the mortars with high content of fly ash were very low, in spite of high total porosity.

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