Frequency-Dependent Electrical Mixing Law Behavior in Spherical Particle Composites
M A. Campo, L Y. Woo, T Mason, Edward Garboczi
The electrical properties of cement-based composites with mono-size conductive (steel) or insulating (glass) spherical inclusions were investigated by combined 2-point impedance spectroscopy and 4-point DC resistance measurements. The matrix was ordinary Portland cement (w/c=0.4; cured for 7 days). Particle loading was varied over an extended range to as high as 42 vol%. The steel particle composites behaved like the glass particle composites at DC and low AC frequencies; conductivity decreased with increasing particle loading. Under AC excitation, however, the steel particles were rendered conductive; conductivity increased dramatically with particle loading. The results were analyzed in terms of various mixing laws and effective media theories and the proposed frequency-switching coating model, which accounts for the unusual frequency-dependent behavior of the steel particle composites.
, Woo, L.
, Mason, T.
and Garboczi, E.
Frequency-Dependent Electrical Mixing Law Behavior in Spherical Particle Composites, Journal of Electroceramics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860410
(Accessed December 2, 2023)