PSI - Issue 42

E. Tziviloglou et al. / Procedia Structural Integrity 42 (2022) 1700–1707 Tziviloglou et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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Nyquist plots of pastes with different xGnP content

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Fig. 4. Typical Nyquist plots of the investigated pastes with different GnP content. The average resistivity values of each of the investigated mixtures (Fig. 5), agree with the hypothesis that the resistivity decreases by adding carbon nanofillers in the cementitious matrix. In this case, the resistivity dropped approximately three times for the two mixtures with lower content of GnPs (0.05 wt% and 0.1 wt%), while the higher GnPs concertation presented resistivity values almost half of that of the reference mixture. The electrical response of the investigated pastes indicates that the critical volume fraction (percolation threshold) that creates a continuous conductive network, which exhibits the lowest resistivity was potentially reached at the lower GnPs concentrations. Moreover, when the GnPs-content increased then the conductive network was possibly interrupted by the formation of GnPs-agglomerates and/or flaws caused by the poor GnPs dispersion.

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Resistivity of pastes with different xGnP content

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Fig. 5. Average electrical resistivity ρ of investigated pastes with different GnP content obtained by AC measurements.