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Diffusion and Pore Structure in Portland Cement Pastes Blended with Low Calcium Fly Ash

Published online by Cambridge University Press:  25 February 2011

Amitabha Kumar
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
Della M. Roy
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802, USA Also affiliated with the Department of Materials Sciences and Engineering
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Abstract

Effective coefficients for the diffusion of Cs+ and Cl ions accross hardened plates of Portland cement and Portland cement-fly ash blend pastes were measured at 27°, 38° and 60° for samples cured up to 28 d. The porosity and pore size distributions of the same hardened plates were also determined. The fly ash blends show lower anion and cation diffusion rates at higher temperatures, although the porosity is not significantly different from the neat paste. The finer pore size is considered responsible for the slower diffusion in the blends. The electronegative nature of the pore surfaces also contributes to the slower cation diffusion.

Type
Articles
Copyright
Copyright © Materials Research Society 1986

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References

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