Identification of corrosion in a prestressed concrete pipe utilizing acoustic emission technique

One of the significant imperfections of prestressed cylinder concrete pipe (PCCP) which leads to fatal failure is corrosion in spiral rebars. The use of PCCP is very widespread, but most often, their instantaneous failures are experienced. In this paper, acoustic emission (AE) technique was employed to detect corrosion in PCCP. To achieve this object three experimental specimens were made in the laboratory of Middle East Technical University. Each specimen was built for the specific aim in which the third one was the almost full-scale sample of PCCP. The pipe was loaded internally by water pressure and accelerated corrosion test was conducted on the specimens. For detecting the corrosion, especially for identifying the passive damages, water pressure was fluctuated during the experiment in both dry and wet conditions along with using the Kaiser Effect phenomenon in both conditions. It was observed that significant changes in some captured AE parameters occur as the pipe pressure exceeds the previous level by which the condition assessment is made feasible. Results indicated that the proposed technique is an efficient procedure for evaluating both active and passive damage types in PCCP.