Acoustic emission characterization of the onset of corrosion in reinforced concrete

The development of techniques capable of evaluating deterioration of reinforced concrete (RC) is instrumental to the advancement of the structural health monitoring (SHM) and service life estimate for constructed facilities. One of the main causes leading to degradation of RC is the corrosion of the steel reinforcement. This process can be modeled phenomenologically, while laboratory tests aimed at studying durability responses are typically accelerated in order to provide useful results within a realistic period of time. Among nondestructive methods, acoustic emission (AE) is emerging as a tool to detect the onset and progression of deterioration mechanisms. In this paper, the development of accelerated corrosion and continuous AE monitoring test set-up for RC specimens are presented. Relevant information are provided with regard to the characteristics of the corrosion circuit, continuous measurement and acquisition of corrosion potential, selection of AE sensors and AE parameter setting. Results from small-scale pre-notched RC specimens aim to isolate the frequency spectrum where the corrosion first takes place. Waveform analysis critical in the definition of a prognosis model will extend the AE dataset for the onset of corrosion.