Conductivity assessment of multifunctional cement pastes by impedance spectroscopy

• Published in: Corrosion science 2021-06, Vol.185, p.109441, Article 109441
• Main Authors: Díaz, Belén, Guitián, Beatriz, Nóvoa, X. Ramón, Pérez, Carmen
• Format: Article
• Language: English
• Subjects: Aspect ratio; Carbon fiber reinforced cements; Carbon fibers; Carbon fibre; Cement; Cement paste; Conductivity; Electrical conduction; Fiber reinforced materials; Fibre aspect ratio; Impedance; Impedance spectroscopy; Mathematical models; Percolation; Reinforced cements; Spectrum analysis
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2021.109441

•An EIS model to study carbon fibre-reinforced cement paste is proposed.•The effect of size and amount of fibre, or the dispersion ability of dispersants, can be assessed.•Milled fibre develop a better dispersion in the cementitious matrix.•Long fibre improve conduction up to a certain concentration (≈0.4 wt%). This study introduces impedance spectroscopy as a technique for reliable assessment of the electrical conduction through a carbon fibre reinforced cement paste. An electrical equivalent model was validated where the polarization response of the fibres is included. Conduction capabilities in addition to other microstructural features, such as the dielectric response or the pore sizes, were obtained using this model. A frequency-independent resistance value was provided since the whole spectrum was considered for the numerical simulations. The variables included in this work were the aspect ratio (milled and chopped) and the amount of fibre. The proposed methodology allows identification of any modification produced of matrix properties, even under the percolation threshold or with a non-uniform fibre dispersion.