In this research, a real-time acoustic emission (AE) monitoring technique was used to record the emitted ultrasonic waves during destruct processes. Column and slab specimens, made of reinforced concrete (RC) and light RC, were tested, analyzed and compared to show their fracture behaviors and relating acoustic (AE) performances. On the specimen surface, AE signals were recorded through 4 sensors at different positions using a self-developed DAQ instrument. The records were counted by second to show the variations in signal density over the load test, and graphed as signal wave-form or FFT as spectrum for fracture event study.

In this paper, some results (slab specimens) revealed “Kaiser effect” and special “intermittent” characteristic would be shown due to the concrete-rebar mechanism and other composite behaviors. In addition, AE signal density variation driven by inner fracture in column would be indicated.