Technology of Data Analysis and Diagnosis for Grout Void Signal in PSC Girder Bridges using Acoustic Emission Technique

This study comprises the additional experiments and analyses used to analyze the trend of acoustic emission variables based on the experimental results of loading and artificial damage to a few abandoned bridges that have been used as actual bridges. The objective was to diagnose and evaluate the safety of the prestressed concrete(PSC) structure using acoustic emission technique. The AE sensor attached to a part of the large PSC structure measured a specific signal of unknown cause in certain parts, and in previous studies, it was estimated as a signal due to grout voids. The grout serves to protect the internal tendon composed of strands installed to introduce the additional compression force to the PSC structure from corrosion, for instance, moisture permeation from outside. During construction, if the grout in the sheath pipe where the internal tendon is located is not sufficient and voids are generated, the stranded wire is exposed to the risk of corrosion, such as moisture penetration. In this study, the acoustic emission test is used to diagnose these phenomena, estimate the location, and analyze the measured acoustic emission signal for early diagnosis and preparation