Identifying the corrosion status of reinforced concrete using cement-based acoustic emission sensors

AE signals generated by the reinforced concrete corrosion process are complex, and the threshold value of common commercial sensors in concrete corrosion monitoring is set high, resulting in the loss of a large number of AE signals. In this article, a homemade cement-based acoustic emission sensor is used to reduce the threshold value to 29 dB. By comparing the acoustic emission signals generated during the accelerated corrosion process of bare steel bars, cement mortar, and reinforced concrete. The research found that the amplitude of the acoustic emission signals caused by steel corrosion was approximately 35 dB, with a main frequency of 150 kHz. The amplitude of the bubble signals generated by corrosion was approximately 30 dB, with a main frequency of 30 kHz. The main frequency of the crack signals caused by the corrosion products of concrete decreased to 110 kHz. The cumulative energy and AE count rise significantly in the later corrosion stages, and the b -value drops below 1 as macro cracks develop. The related technologies have potential research value in identifying the corrosion stage of reinforced concrete and reducing maintenance costs.