Thermoelectric percolation phenomena in carbon fiber-reinforced concrete

Abstract The measurements of thermoelectric power (TEP) and conductivity on carbon fiber-reinforced concrete (CFRC) containing short polyacrylonitrile-based carbon fibers (0.2–2.0 wt.%) were conducted. Percolation phenomena in CFRC associated with TEP were observed. TEP in CFRC increases, with the content of short carbon fiber increasing from 0.2 to 1.0 wt.%. As the content of carbon fiber reaches 1.2 wt.%, TEP decreases abruptly. In the end, TEP is almost maintained marginally with increasing content of carbon fiber from 1.4 to 2.0 wt.%. Therefore, the threshold is 1.2 wt.%, which is the same as the percolation content associated with conductivity. The results provide an important guide for the manufacture of smart concrete that has the ability for thermal self-diagnosis.