Cement as a thermoelectric material

Cement pastes containing short steel fibers, which contribute to electron c onduction, exhibit positive values (up to 68 muV/degreesC) of the absolute thermoelectric power. Cement pastes containing short carbon fibers, which c ontribute to hole conduction while the cement matrix contributes to electro n conduction, exhibit negative or slightly positive values of the absolute thermoelectric power. The hole and electron contributions in carbon fiber r einforced cement paste are equal at the percolation threshold. Addition of either steel or carbon fibers to cement paste yields more reversibility and linearity in the variation of the Seebeck voltage with temperature differe nce (up to 65 degreesC).