Novel Application of Voltammetric Sensors to Characterize the Electrochemical Behavior of Porous Media

High Resolution Image Download MS PowerPoint Slide The objective of this study is to assess the feasibility of using embedded voltammetric sensors for the electrochemical characterization of porous materials, specifically concrete, and to analyze how environmental conditions influence their response. Cyclic voltammograms were recorded in solutions simulating various pore-solution conditions of concrete as well as in concrete specimens under different states (water-saturated, carbonated, and chloride-contaminated), using a gold electrode as the sensing element. The morphology of the voltammograms and characteristic electrochemical parameters (peak current and potential, Δ E p, i B / i b, α n, R u ) were examined to identify similarities and differences in the sensor’s behavior across both environments. Subsequently, principal component analysis (PCA) was applied to evaluate the reproducibility of the response and the sensor’s discriminating capability in a porous medium such as concrete. The results indicate that the identified redox process, associated with OH – adsorption/desorption, preserves its electrochemical nature in both environments; however, in concrete, the control mechanism shifts from quasi-reversible to diffusion-kinetic, governed by ionic resistance and the tortuosity of the pore network. The PCA results demonstrate that the embedded sensor effectively differentiates between reference, carbonated, and chloride-contaminated concrete, confirming its potential as a nondestructive diagnostic tool for in situ electrochemical monitoring of porous materials containing interstitial moisture.