Seebeck Effect in Graphite-Carbon Fiber Cement Based Composite

The Seebeck effect in carbon fiber reinforced cement-based composite (CFRC) is of interest because it enables the cement-based materials to sense its own temperature without attached or embedded sensor. In this study, the Seebeck coefficient of CFRC and graphite-carbon fiber cement based composite were measured. Results show that the addition of graphite can enhance the Seebeck effect of CFRC. When graphite content is 10wt. %, all types of CFRC show P-type because the hole contribution from carbon fiber dominates the Seebeck effect. When the graphite content is 20wt. %, the change of thermoelectric power (TEP) from positive to negative occurs with the increasing of graphite to carbon fiber ratio (>= 25). This phenomenon indicates that compensation takes place between electron contribution from graphite and hole contribution from carbon fiber. At a high graphite content (30wt. %), CFRC shows N-type above a certain temperature difference (20-25 degrees C) since the electrons from graphite dominate the Seebeck effect.