###### Abstract
However, the end of the CFRP plates is prone to stress concentration, which may lead to the appearance of debonding cracks in the early loading stage. Debonding failure initially occurs as very small cracks, which then propagate to other parts of the structure, ultimately leading to the brittle failure of the structure [8]. The accumulation of the following factors may cause brittle failure during extreme events: dynamic loads due to moving vehicles [9], corrosions [10] and impact loading [11]. It is difficult to take remedial measures in time without obvious warning before the failure, which may result in unwanted consequences. The brittle failure of the structure indicates that the CFRP plate is far below the ultimate tensile strength and the utilization ratio is low, which causes a great waste of material. Therefore, it is desirable to develop a reliable monitoring system to detect the interface bonding condition of RC structure with NSM pre-stressed CFRP plates. The ultimate failure of the structure is caused by the debonding between the CFRP and concrete. Therefore, it is particularly important to monitor the initial debonding damage using an effective non-destructive testing (NDT) technique. In order to ensure a secure connection between CFRP and concrete, it is extremely urgent to find reliable, convenient and economical technical means to monitor the interface performance between CFRP and concrete. This can help to take further measures in time to avoid serious failure. At present, it is difficult to predict the failure of components under better linear behavior by using traditional strain and deflection measurement methods. Other NDT techniques in civil engineering include acoustic inspection technology [12], ultrasonic method [13], vibro-acoustic technique [14], infrared thermography [15], impact-echo approaches [16], microwave-based methods [17], ground penetrating radar techniques [18], fiber optic sensing [19] and among others. [PERSON] et al. have demonstrated the bearing mechanism and debonding damage process of FRP and self-compacting concrete by using acoustic inspection technology through experimental research [20]. [PERSON] et al. discusses the feasibility of using the impact-echo method to assess the debonding flaws at the epoxy-concrete interfaces of near-surface mounted CFRPs [21]. However, this method requires the preparation of debonding defects for experimental research, which loses the randomness of structural damage. At the same time, the structural form commonly used in engineering is not adopted and only small sized specimen columns are prepared for testing. [PERSON] et al. verified the feasibility of near-field microwave detection technology by monitoring the defects and debonding between CFRP and strengthened structures based on experimental studies [22]. These techniques are demonstrated to successfully monitor defects and debonding in the reinforced concrete structures strengthened with CFRP. However, the above-mentioned monitoring technology requires complicated algorithms, huge equipment and high cost, making online real time monitoring impossible. The emergence of smart materials has the potential to overcome most of the shortcomings of traditional structural inspection techniques [23]. Piezoceramic materials are new smart materials widely used in recent years. Piezoceramic Lead Zirconate Titanate (PZT) has the advantages of wide frequency response range, fast response and low price. Based on the excellent characteristics, piezoceramic PZT transducers are not only widely used in communications, aerospace, radar, ultrasound and other fields but also provide a new research direction for civil engineering health monitoring. The price of structural health monitoring (SHM) based on piezoceramic PZT is low and extensive application in the field of civil engineering can bring good economic benefits. Therefore, many scholars have conducted extensive research on the health monitoring of CFRP-reinforced structures based on piezoceramic transducers.