Electrochemical immittance spectroscopy applied to a hybrid PVA/steel fiber engineered cementitious composite

Abstract Alternating current (a.c.) electrical property measurements are presented on an Engineered Cementitious Composite (ECC) reinforced with a hybrid mix of polyvinyl alcohol fibers (fixed dosage) and straight steel fibers of varying dosages (0.15–1.0% by volume), with the aim at elucidating the influence of conductive inclusions on the nature of conduction and polarization processes within the composite. Measurements were undertaken over the frequency range 1 Hz–10 MHz at 7, 14 and 28 days after casting and the data presented in a range of formalisms to aid interpretation. When plotted in the frequency domain, the work shows that steel fibers enhance the polarizability of the material, particularly within the frequency range ~ 10 Hz–10 kHz. When presented in Nyquist format, this feature manifests itself as an intermediate arc forming between a high frequency arc (> 10 kHz) and a low frequency arc (