Experimental Detection of Reinforcing Bar Corrosion Using Nondestructive Geophysical Techniques

Abstract

This research used electrical impedance and ground penetrating radar (GPR) methods to indicate corrosion of steel reinforcing bars embedded in a concrete block. Corrosion of the reinforcing bars was accelerated using an anodic polarization technique. Measurements were collected using both geophysical techniques before and after the corrosion experiments. Analysis of the geophysical measurements indicated the potential benefits and limitations of the 2 geophysical methods for assessing corrosion of reinforcing bars. GPR methods have the advantage of providing a quick indication of alterations at the interface of the rebar surface and the surrounding concrete, and they have the potential to yield very high spatial resolution data. Indications that corrosion had occurred were independently and consistently obtained from the 2 geophysical methods, and observations were also corroborated by visual examination of the rebar corrosion state by destructive analysis of the experimental block.