Acoustic-Emission-Based Characterization of Corrosion Damage in Cracked Concrete with Prestressing Strand

An accelerated corrosion study to assess the feasibility of acoustic emission (AE) for the detection of active corrosion in prestressing strand is described. Concrete prisms with an embedded steel strand were corroded by supplying a constant potential between the strand and a copper plate while the specimens were immersed in a 3% NaCl solution. Corrosion was detected using the half-cell potential (HCP), steel section loss, and visual inspection, and the results were compared to AE data. The location of active corrosion was determined experimentally based on the characteristic wave speed. An intensity analysis approach was used to plot the relative significance of the corrosion damage and a classification chart is presented. Results indicate that AE is a useful, nonintrusive technique for the detection and quantification of corrosion damage and may be developed as a structural prognostic tool for maintenance prioritization.