TY - JOUR
T1 - Impedance spectroscopy of fiber-reinforced cement composites
AU - Mason, T. O.
AU - Campo, M. A.
AU - Hixson, A. D.
AU - Woo, L. Y.
N1 - Funding Information:
This work was supported in part by the National Science Foundation Science and Technology Center for Advanced Cement-Based Materials under grant no. CHE-91-20002 and by the National Science Foundation under grant no. DMR-00-73197.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/10
Y1 - 2002/10
N2 - The addition of chopped conductive fibers to cement matrices results in a characteristic "dual-arc" electrical impedance spectrum below the percolation threshold. This behavior can be explained on the basis of a "frequency-switchable fiber coating" model, in which a "coating" (e.g., passive oxide film on steel or charge transfer resistance/double layer on other conductors) insulates the fibers at DC and low AC frequencies, but is shorted out at higher frequencies, where the fibers become short-circuit paths in the composite microstructure. The present work investigates various factors governing the impedance spectra of fiber-reinforced cement composites - fiber aspect ratio, fiber volume fraction, fiber orientation (relative to field direction), and fiber shape. The "gamma" factor (ratio of the low frequency arc diameter to DC resistance) is a useful parameter to characterize the microstructure-property relationships of fiber-reinforced composites.
AB - The addition of chopped conductive fibers to cement matrices results in a characteristic "dual-arc" electrical impedance spectrum below the percolation threshold. This behavior can be explained on the basis of a "frequency-switchable fiber coating" model, in which a "coating" (e.g., passive oxide film on steel or charge transfer resistance/double layer on other conductors) insulates the fibers at DC and low AC frequencies, but is shorted out at higher frequencies, where the fibers become short-circuit paths in the composite microstructure. The present work investigates various factors governing the impedance spectra of fiber-reinforced cement composites - fiber aspect ratio, fiber volume fraction, fiber orientation (relative to field direction), and fiber shape. The "gamma" factor (ratio of the low frequency arc diameter to DC resistance) is a useful parameter to characterize the microstructure-property relationships of fiber-reinforced composites.
KW - Carbon fiber composites
KW - Electrical impedance spectroscopy
KW - Steel fiber composites
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U2 - 10.1016/S0958-9465(01)00077-4
DO - 10.1016/S0958-9465(01)00077-4
M3 - Article
AN - SCOPUS:0036778815
VL - 24
SP - 457
EP - 465
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
SN - 0958-9465
IS - 5
ER -