Corrosion Damage Quantification of Prestressing Strands Using Acoustic Emission: Fid-Bau Portal

Corrosion Damage Quantification of Prestressing Strands Using Acoustic Emission

Mangual, Jesé / ElBatanouny, Mohamed / Ziehl, Paul / Matta, Fabio

Steel degradation due to corrosion in prestressed concrete bridges has been of major concern as it presents a threat to the integrity of structures adjacent to marine environments or where deicing salts are regularly used. To assess the potential for monitoring of the corrosion process, an accelerated corrosion testing program has been conducted. A series of specimens with dimensions $114 \times 114 \times 508 mm$ ( $4.5 \times 4.5 \times 20 in.$ ) were subjected to constant potential application through the embedded steel strand while being continuously monitored with acoustic emission (AE). Depassivation of the strand was detected by monitoring the fluctuations in applied anodic current. Half-cell potential measurements assessed the probability of corrosion, and all results obtained were compared to acoustic emission data. The mass loss of the corroded strands was correlated to acoustic emission intensity analysis to quantify the degree of damage. Results show that acoustic emission is as sensitive as half-cell potential for detecting the presence of corrosion and may be used to effectively locate corroded areas. The intensity analysis proved useful for categorizing the level of damage, making it a strong candidate for structural prognosis.