Damage Assessment in Deteriorated Cracking Concrete using AE Double Logistic Analysis under Compressive Stress Field

Mechanical core samples. However, the mechanical properties do not always correspond to degree of internal damage. Acoustic Emission (AE) signals are produced by the process causing deterioration. In this study, we focused on the relationship between AE energy release behavior and the internal structure of deteriorated concrete cores under a compressive stress field. These cores were drilled from a reinforced concrete headworks structure, which was constructed about 50 years ago. X-ray Computed Tomography (CT) was used to quantify the internal structure. Accumulated was quantitatively evaluated using inflection point information of cumulative AE energy curve, which was derived from AE double logistic analysis.

As a result, the testing cores were classified into two groups according to crack area ratio. Different AE energy release behaviors were detected depending on the maximum strain energy of cores with lower crack area ratio. High AE energy release occurred at an early stage in cores with higher maximum strain energy. The same behavior was observed during the middle to later stages in cores with lower maximum strain energy. In the low crack area ratio group, a significant positive correlation is confirmed in the right-bank pier cores between the crack area ratio and strain energy level at first inflection point of the cumulative AE energy curve (R² = 0.691, p < 0.05). No similar correlation is identified in the high crack area ratio group. The difference indicates that degree of damage in cores is linked to AE energy release behavior.