Study on the acoustic characteristics of corrosion damage of reinforced concrete materials used in highway bridges

Abstract Reinforced concrete is a critical component of concrete bridges. This study employs an embedded cement-based acoustic emission (AE) sensor to investigate the relationship between corrosion rate, durability and acoustic emission characteristics of the samples, based on the theory of corrosion stress waves. At the initial stage of corrosion, variations in corrosion rate have the most significant impact on the AE characteristics of the samples. When the corrosion rate increased from 5 to 15 V, the abrupt change time of cumulative AE energy advanced by 2 days. This trend was primarily determined by the failure mode at each corrosion stage and was minimally influenced by concrete strength. As the degree of corrosion increased, the peak main frequency shifted from 250 to 50 kHz, while the waveform peak amplitude rose from 0.53 mV to 1.87 mV. A concrete bridge damage risk warning model was developed by utilizing cumulative energy transition points as warning thresholds, integrated with the correlation between specimen durability and AE characteristics. This model enables the assessment of deterioration of reinforced concrete deterioration under varying corrosion rates, offering a novel technical approach for disaster early warning and rational maintenance strategies for highway bridges.