Abstract
The aim of this study is to investigate the reproducibility of electro heat-generation that has been the biggest problem of electro heat-generation mortar. At first, electric properties, such as heat-generation, electric resistance, electric current and temperature coefficient, of electro heat-generation mortar mixing amorphous graphite were investigated under various curing conditions. The electric properties of electro heat-generation mortar was secondly investigated under various shapes of specimen. As a result of the study, the maximum temperature of mortar was higher in curing conditions of steam curing and wet curing. In case of Amorphous graphite addition of 50% and at age of 7 days, the maximum temperature of wet-cured and steam-cured specimens were respectively $99.8^{\circ}C$ and $83.1^{\circ}C$, while autoclave-cured and dry-cured specimens showed the maximum temperature of $60.0^{\circ}C$ and $60.9^{\circ}C$. The temperature coefficient of mortar with graphite addition of 50% was showed positive level similar with metals, while the temperature coefficient of mortar with graphite addition of 35% was showed negative level similar with carbon and electrolyte. It is finally analyzed that the mortar specimen with graphite addition of 50%, cross-section area of $9.0cm^2$ and length of 74cm~158cm is most effective for heat-generation in this study.
