Relationship between the transfer properties of the coating and impedance spectroscopy in reinforced cement-based materials

This study highlights the relationships between some transfer properties of cement-based material, which coats reinforcing steel and its impedance response in High Frequency domain. Transfer properties are mainly represented by the coating thickness, its chloride diffusion coefficient and its porosity. The diffusion coefficient and the porosity are linked to the w/c ratio. Results have shown that the impedance spectroscopy is a pertinent non-destructive tool to characterize the cement-based materials coating. For reasons of long time consuming, tests were limited to coatings made of cement pastes with low thickness. It seems desirable to extend the study to concrete coatings that are more representatives of real structures. Indeed, the closed relationships highlighted by the results make this methodology possible to be implemented on the case of concrete structures in order to optimize the monitoring with a non-destructive way of the maintenance and the repairs of working concrete structures.