Effect of fiber content on the thermoelectric behavior of cement

The effect of discontinuous stainless steel fibers (diameter 60 μm) as an admixture in cement paste on the thermoelectric behavior (the Seebeck effect) was systematically studied as a function of fiber volume fraction from 0 to 0.50 vol%. Without fibers, cement paste has an absolute thermoelectric power of +3 μV/°C. A fiber content of up to 0.20 vol% makes the absolute thermoelectric power more negative (down to -63 μV/°C), whereas a fiber content of 0.20-0.50 vol% makes the absolute thermoelectric power more positive (up to +31 μV/°C) - even more positive than the positive value for the steel fiber by itself (+8 μV/°C). The value is zero at a steel fiber content of 0.27 vol%. The effects are probably due to carrier scattering rather than conduction.