Development in a novel technique to assess fly-ash content of fresh concrete

摘要

Immittance spectroscopy is exploited to gain understanding of electrical conduction and polarization within OPC-Fly Ash (FA) binders in the frequency range 1Hz-1MHz. On a Nyquist diagram, the FA binders display a characteristic three region impedance response. Correspondingly, a region of dispersion, superimposed on that observed for plain OPC binder, was evident for OPC-FA systems in the frequency domain dielectric constant and conductivity. The extent of dielectric constant enhancement attributable to the presence of FA was found to be approximately linearly related to the FA proportion in the binder. It is proposed that double layer polarization on the FA grains could be responsible for the impedance response.