Discrimination of crack types in reinforced concrete beams by acoustic emission

摘要

The acoustic emission (AE) technique was investigated in reinforced concrete (RC) beams to distinguish types of cracks, such as bending, shearing and bond between reinforcing steel bars and concrete. Several model tests were carried out tocharacterize the AE signals caused by these cracks. The result of moment tensor analysis showed that particular cracks were dominant in each model test. Then, to establish a simpler distinction method, AE waveform parameters were employed as evaluationindices, so that the peak amplitude and the average frequency of AE signal detected were effective for discriminating the crack types. Finally, AE measurement was performed during the bending test on the mock-up of RC beams to verify the validity of theresults of model tests. These two parameters made it possible to appropriately distinguish the various cracks occurring during the failure process of RC beams.