As part of developing that understanding, the objective of this work is the experimental and modeling analysis of steel in concrete in the passive state, in response to the application of cathodic cyclic polarization with polarization rates in the order of 0.001 mV/sec and polarization down to -300 mV with respect to the (passive) corrosion potential. This technique, implemented with higher polarization rates after appropriate adjustment as a refined form of Tafel extrapolation, is a possible candidate to monitor structures of interest. In order to interpret the passive corrosion process response to polarization excitation, a modified Randles interphase model analog was used. A novel feature of this study is the introduction of large amplitude time domain behavior of a constant phase angle element, which is then combined with the large amplitude response of the Faradaic current treated with a Butler-Volmer approach. The system steel/interface/concrete is described by a fractional order differential equation that is solved by the implementation of a finite differences aproach. Comparisons between the experimental results from multiple specimens at various scan rates and the response calculated by solution of the equations of the system were made, showing good agreement between both. Corrosion current densities obtained by numerically fitting the model to experimental results yielded values typically lower than 10-8 A/cm2 in agreement with other values reported in the literature for long term exposures of passive steel in concrete. Open issues on the applicability of these results for mechanistic interpretation of the processes at work on the rate of passive dissolution of steel in concrete are discussed.