Title:
Evaluation of the AC Conductivity and the Percolation State in Cementitious Materials Based on Alumina Slag
Author(s):
José Luis Ochoa M., Stephani Voelger S., and Adrián R. Arias P.
Publication:
Symposium Paper
Volume:
362
Issue:
Appears on pages(s):
215-239
Keywords:
AC alternating electric field, alumina slag, cment, complex system, conductivity, dielectric system, loss, percolation, permittivity
DOI:
10.14359/51740885
Date:
6/5/2024
Abstract:
A dielectric system is considered in this work. The system is made up of a mechanical mixture based on cement and additions of alumina slag. The mixture has been hydrated with an optimum experimental water/cement ratio equal to 0.33. For different curing times, the system is made up of randomly distributed metallic and dielectric regions; thus forming a solid, “dry”, porous, and chaotic dielectric system, therefore, complex. For the electrical characterization, the system has been subjected to the action of an alternating electric field with the frequency (7 VRMS, f: 5 Hz to 0.5 MHz), using electrical impedance spectroscopy as a measurement method. The electrical conductivity and the dielectric permittivity are determined as a function of the frequency and composition. It was found that the morphology of the conductivity curves shows the existence of a percolation state. Furthermore, following their evolutionary line, they can be represented as a power law of percolation. The permittivity and dielectric loss curves allow us to determine the threshold frequency, which marks the beginning of the percolation state. The mechanical resistance allowed determining the elastic modulus and the volumetric deformation.