Damage Evaluation for Concrete Bridge Deck by Means of Stress Wave Techniques

Damage Quantification in Concrete under Fatigue Loading Using Acoustic Emission

“…It reveals that the predicted results agree with the experimental results, and the proposed method is able to capture the mechanisms of damage accumulation. In addition, by submitting the predicted results of the damage variable into the BCM (equations (12), (15), (16), (17), and (19)), the predictions of the deterioration behaviors are obtained in Figure 6. It illustrates that the predictions of the proposed method agree with the experimental results.…”

“…However, few works in the literature have focused on one quantification method of damage in concrete under fatigue loading by using AE for characterizing the entire three deterioration behaviors simultaneously. Specifically, most contributions only considered the experimental investigations on the empirical relationship between a single deterioration behavior and a certain AE parameter [13][14][15][16][17][18][19]. For instance, Wang et al [15] conducted the comparison on the fatigue properties among plain concrete, rubberized concrete, and polypropylene fiber-reinforced rubberized concrete by applying AE, and the results showed a linear correlation between the AE counts and the residual strain for plain and rubberized concrete, respectively.…”

Interpretation of Fatigue Damage Evolution in RC Slabs by Means of Innovative 3D AE Tomography

“…The authors have been thus studying the inspection methods being effective to the invisible damages as well as the damage indices, based on the elastic wave properties [1], [2]. Specifically in the following the damage index, namely Q-value is introduced, followed by the innovative visualization technique, AE tomography solving both of locations of AE sources as well as velocity distributions.…”

“…So far the authors have studied the damage of the structures using such elastic wave methods as an AE technique and UT tomography. In the AE applications, we succeeded to relate the frequency features of AE waveforms to damage [1], and in UT applications it has been clarified that those parameters as elastic wave velocity, an attenuation rate of amplitude, and frequency, could be indices of damage evaluation [3][4][5][6]. However, as for the velocity and the amplitude, it is known that the former are dependent on the frequency and the latter is readily decayed with propagation distance.…”

“…In the apparatus there is a steel wheel of 300 mm in diameter and 400 mm in width and can be applied the load up to 250 kN in the case of dynamic and 534 kN in the case of static load in the vertical direction. Contrary to the conventional wheel loading machine with a movable loading wheel [1], the foundation where the specimen is installed, is moved in the longitudinal direction within ±500 to ±1000 mm (±500 mm in this test). The repetition rate can be set between 0.897 -9.97 rpm/ min (8.97 rpm in this test).…”