TY - JOUR
TI - Experimental and theoretical approach to determination of heat evolution in electrically conductive aluminosilicates
AU - Fiala Lukáš
AU - Maděra Jiří
AU - Černý Robert
JN - Thermal Science
PY - 2020
VL - 24
IS - 2
SP - 787
EP - 794
PT - Article
AB - Design of progressive building materials with increased utility value is the  key issue for the development of reliable modern building structures.  Compared to the conventional materials, progressive building materials are  supposed to exhibit not just adequate mechanical, and thermal properties,  but they are also supposed to be applicable in sophisticated solutions, such  as in self-sensing, self-heating or magnetic-shielding systems. In terms of  electric properties, the most of building materials are electric insulators  which is the main limiting factor for their applicability in such  sophisticated solutions. However, this deficiency can be solved by the  addition of a proper amount of electrically conductive admixtures. Within  the paper, electrically conductive alkali-activated aluminosilicate with  8.89 mass% of carbon black admixture was designed and its materials  properties necessary for calculations of heat evolution by the action of an  electric source were experimentally determined. The electrical conductivity  of such material equal to 5.57×10-2 S m-1 was sufficiently high to ensure  self-heating ability. It was observed good agreement of experimentally  determined data with those modeled by means of heat equation on sample with  dimensions 40 × 40 × 10 mm. Finally, one- and two-layered large-scaled  heating elements based on materials with experimentally determined  properties were designed and calculations were conducted to determine the  voltage level necessary for one-hour heating from 268.15 K and 273.15 K to  278.15 K in the middle-top point of the construction.