Fabrication and electrical properties of carbon fiber, graphite and nano carbon black conductive cement-based composites

Carbon fiber (CF) is one of the conductive fillers with the best electrical conductivity, but it is expensive and difficult to disperse in cement matrix, which limits the application and development of CF conductive cement-based composites. Therefore, this paper took the conductive cement slurry with CF content of 1.0 % as the control group, and proposed to use low-cost graphite (G) and nano-carbon black (NCB) instead of some CFs to prepare conductive cement-based composites. The synergistic enhancement effect between different conductive fillers was explored to reduce the cost of materials while maintaining electrical conductivity. The results showed that the resistivity decreased first, then increased, then decreased and then increased with the increase of the proportion of particle conductive filler instead of CF. The resistivity of conductive cement slurry was 125.65 Ω·cm when G replaced 20 % CF, the resistivity of conductive cement slurry was 140.66 Ω·cm when NCB replaced 30 % CF, and the resistivity of conductive cement slurry was 122.05 Ω·cm when G and NCB replaced 30 % CF, which were close to the resistivity of the control group (122.35 Ω·cm). The purpose of reducing the cost of materials without affecting the conductivity of conductive cement slurry was achieved.