Abstract
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% volume fraction. 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-switchable coating model," which accounts for the unusual frequency-dependent behavior of the steel particle composites.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 49-56 |
| Number of pages | 8 |
| Journal | Journal of Electroceramics |
| Volume | 9 |
| Issue number | 1 |
| DOIs | |
| State | Published - Oct 2002 |
Keywords
- Cement
- Composites
- Electrical conductivity
- Impedance
- Mixing laws
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Mechanics of Materials
- Electrical and Electronic Engineering
- Materials Chemistry