Effect of the Interfacial Transition Zone on the Conductivity of Portland Cement Mortars.
Effect of the Interfacial Transition Zone on the
Conductivity of Portland Cement Mortars.
Garboczi, E. J.; Bentz, D. P.; Shane, J. D.; Mason, T.
O.; Jennings, H. M.
Journal of the American Ceramic Society, Vol. 83, No.
5, 1137-1144, 2000.
portland cement; mortar
The electrical conductivity of portland cement mortars
was determined experimentally as a function of the
volume fraction of sand and the degree of hydration. The
results were analyzed using theoretical models that
represent the mortars as three-phase, interactive
composites. The three phases are the matrix paste, the
aggregate, and the thin interfacial transition zone
between the two. The microstructure and properties of
the conductive phases (the transition zone and the
matrix paste) were determined by a micrometer-scale
microstructural model, and were used in conjunction with
random-walk algorithms and differential-effective medium
theory to determine the overall mortar conductivities.
The presence of the transition zone was not found to
significantly affect the global electrical conductivity
of the mortar. However, there were significant
differences in conductivity between the transition zone
and matrix pastes when examined on a local level. These
differences were found to vary with hydration and were
most significant when the degree of hydration was
between 0.5 and 0.8.