Intrinsic Conductivity of Short Conductive Fibers in Composites by Impedance Spectroscopy.
Intrinsic Conductivity of Short Conductive Fibers in
Composites by Impedance Spectroscopy.
Hixson, A. D.; Woo, L. Y.; Campo, M. A.; Mason, T. O.;
Garboczi, E. J.
Journal of Electroceramics, Vol. 7, 189-195, 2001.
fibers; composite materials; electrical conductivity;
Electrical property measurements (DC conductivity,
impedance spectroscopy) were employed to determine the
"intrinsic conductivities" of short conductive fibers in
cement matrix composites. Intrinsic conductivity
determines the variation of overall conductivity (DC or
AC) vs. volume fraction of fibers. Model composites
consisting of steel wires (0.5 mm diameter), but with
aspect ratios comparable to typical carbon or steel
fibers used in cement/concrete, were shown to exhibit
similar "dual arc" impedance spectra as observed in
actual composites. The results were compared with
existing exact calculations for composites with randomly
distributed right cylinders. The conductivity vs. aspect
ratio behavior can be used to estimate the aspect ratio
in randomly distributed fiber composites.