%0 Conference Paper %F Oral %T Influence of silica fume and water content on the microstructure and diffusion parameters of cement pastes %+ CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)) %+ Laboratoire de Mécanique et Technologie (LMT) %A Bajja, Z. %A Dridi, W. %A Darquennes, A. %A Bennacer, R. %< avec comité de lecture %B 4th International Conference on Sustainable Construction Materials and Technologies %C Las Vegas, United States %8 2016-08-07 %D 2016 %K Microstructure %K Tritiated water diffusion %K Cement paste %K Slurried silica fume %K Durability %Z Physics [physics]/Nuclear Experiment [nucl-ex] %Z Physics [physics]/Nuclear Theory [nucl-th]Conference papers %X Durability of silica fume cement based materials is of great importance for radioactive wastestorage. This study investigates the durability in the aspect of tritiated water (HTO) diffusion inrelation with the porosity and the microstructure within silica fume cement pastes. A silica fume(SF) replacement varying from 0 to 20% by weight of cement was used to prepare cement pastesat water-to-binder ratios (w/b) ranging from 0.3 to 0.5. The manufactured pastes were tested bythrough-out diffusion and their microstructure characterized by water and mercury porosimetry(MIP), thermogravimetric analysis (TGA) and by scanning electron microscopy (SEM)associated to (EDS) analysis.It was observed that the addition of silica fume as a slurry –a liquid mixture of undensifiedpowder and water- offers a better dispersion and improves diffusion properties of SF pastescompared to the use of a densified powder, often studied in literature.Test results also showed that despite an increase in total porosity, the addition of silica fume hasa positive impact on pore refinement and on reducing the effective diffusion coefficients.Finally, HTO diffusion coefficients seem to increase linearly with w/b ratio especially forPortland cement pastes where the increase is more important compared to SF pastes. %G English %2 https://cea.hal.science/cea-02509801/document %2 https://cea.hal.science/cea-02509801/file/201500004675.pdf %L cea-02509801 %U https://cea.hal.science/cea-02509801 %~ CEA %~ CNRS %~ ENS-CACHAN %~ LMT %~ DEN %~ UNIV-PARIS-SACLAY %~ ENS-CACHAN-SACLAY %~ SORBONNE-UNIVERSITE %~ SU-SCIENCES %~ LMT-SACLAY %~ SU-TI %~ FARMAN %~ ENS-PARIS-SACLAY %~ ENS-PSACLAY %~ GS-ENGINEERING %~ ALLIANCE-SU %~ LMPS