Carbon fiber reinforced concrete as an electrical contact material for smart structures

Concrete containing 0.2-0.4 vol.% short carbon fibers was found to exhibit volume electrical resistivity of 10³-10⁵Ω cm and contact resistivity (between the cured concrete and stainless steel) of 10 ³-10⁶Ω cm at zero contact pressure. Increasing the contact pressure from 0 up to 0.05 MPa was sufficient to lower the contact resistivity to a minimum value. Increasing the fiber content to > 0.4 vol.% did not decrease the contact resistivity, but decreased the volume resistivity. The values of the volume and contact resistivities depended on the non-fiber additives (i.e., latex, methylcellulose and silica fume) needed for fiber dispersion. Using latex gave a higher volume resistivity (1 × 10 ⁵Ω cm) and a lower contact resistivity (5 × 10 ³Ω cm²) than methylcelluiose and silica fume; the high volume resistivity was due to the large proportion of latex used; the low contact resistivity was due to the lack of adherent on the surface of fibers protruding from the concrete containing latex.