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Search Publications by: Andrew J Allen (Fed)

Displaying 251 - 258 of 258

Determination of the Neutron Scattering Contrast of Hydrated Portland Cement Paste Using H 2 0/D 2 0

June 1, 1998

Author(s)

J Thomas, Hamlin M. Jennings, Andrew J. Allen

Accurate measurements of the surface area of cement based materials using small-angle neutron scattering (SANS) require determination of the neutron scattering contrast between the C-S-H gel and H6d2^O. Because the C-S-H gel has a poorly understood

Anisotropic Microstructure of Plasma-Sprayed Deposits

April 1, 1998

Author(s)

J Ilavsky, Gabrielle G. Long, Andrew J. Allen, L Leblanc, M Prystay, C Moreau, Alan H. Band

The microstructure of plasma-sprayed deposits [PSD] is dominated by two void systems-interlamellar pores and intralamellar cracks - each with a different anisotropy. Varying anisotropies and crack-to-pore ratios within PSDs are responsible for the

USAXS Studies of Silica Fume Additives in Cements and Concrete

April 1, 1998

Author(s)

Andrew J. Allen, Richard A. Livingston

Supplementary cementitious materials like silica fume, which are added to the cement mix and react with calcium ions in the pore solution, enhance the production of calcium-silicate-hydrate gel and modify the microstructure in other ways. By combining

Evolution of the Microstructure of Plasma-Sprayed Deposits During Heating

January 1, 1998

Author(s)

Gabrielle G. Long, Andrew J. Allen, J Ilavsky

The evolution of the void microstructure of yttria-stabilized zirconia [YSZ] plasma-sprayed deposits [PSD] was studied as a function of heating in air from room temperature to 1400 C, and during a constant temperature hold at 1100 C for 19 hours. The

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