Research on Acoustic Emission Characteristics of Deterioration Reinforced Concrete Beams During Bending Load Failure

In order to investigate the acoustic emission (AE) characteristics of deteriorated reinforced concrete beams during bending load failure, three-point bending test was conducted on four reinforced concrete beams with varying degradation level simulated through freeze-thaw and corrosion cycle. AE parameters of reinforced concrete beams with different degradation level during bending load failure were analyzed, and the influence of deterioration level on AE parameters was revealed. The results show that the maximum cumulative ringing counts and AE energy decrease with degradation degree increasing. High-amplitude signal appears earlier comparing with that of nondeterioration beam. As deterioration degree continues to increase, the proportion of AE events with low rise-time continuously decrease, and proportion of AE events with high rise-time (rise time > 150μs) exhibits a continuously increasing trend. Freeze-thaw and corrosion deterioration significantly reduce the strength and toughness of reinforced concrete beams, which causes significant changes in AE parameters. Therefore, the influence of deterioration should be considered in damage identification and early warning for in-service reinforced concrete bridge by using AE technology.