Corrosion monitoring of the RC structures in time domain: Part I. Response analysis of the electrochemical transfer function based on complex function approximation

• The response of Rc((RctZW)ZCPE) equivalent circuit in time domain is analyzed.
• The complex-function-approximation algorithm is established.
• Influence of the dispersion and diffusion effects is investigated in time domain.

To finally obtain the overall and fast recognition method for the electrochemical corrosion of reinforced concrete (RC) structures, the complex function algorithm is established to approximate the corrosion transfer function in frequency domain, and then the influence of ZCPE, ZW, Rct and Rc in the universal equivalent circuit (EC) Rc((RctZW)ZCPE) on the time response is discussed in detail. The results indicate that the polynomial complex function can successfully approximate the corrosion transfer function with the given accuracy. The response of Rc((RctZW)ZCPE) in time domain can be achieved by the inverse Laplace transform of the polynomial complex approximation function.