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Recently, there have been lots of research and development activities to confirm the reliability in terms of the healthy condition for hanger cables of suspension bridges. However, little research about non-destructive evaluation (NDE) techniques for main cable of the suspension bridges has been carried out. In this context, this study proposes a new methodology incorporating DC magnetization with a search coil-based total flux measurement to investigate the loss of the cross section of the main cable due to corrosion damage. From the hysteresis curve of the magnetized main cable measured at the search coil of the proposed NDE equipment, a quantification algorithm to estimate the loss rate of the main cablesÕ cross section is induced. The feasibility of the proposed NDE methodology is verified throughout an experimental study using a real scaled cable specimen with artificially inflicted broken wires.

Recently, demands for the construction of Nuclear Power Plants (NPP) using high strength concrete (HSC) has been increased. However, HSC might be susceptible to brittle fracture if the curing process is inadequate. To prevent unexpected collapse during and after the construction of HSC structures, it is essential to confirm the strength development of HSC during the curing process. However, several traditional strength-measuring methods are not effective and practical. In this study, a novel method to estimate the strength development of HSC based on electromechanical impedance (EMI) measurements using an embedded piezoelectric sensor is proposed. The EMI of NPP concrete specimen was tracked to monitor the strength development. In addition, cross-correlation coefficient was applied in sequence to examine the trend of the impedance variations more quantitatively. The results confirmed that the proposed technique can be applied successfully monitoring of the strength development during the curing process of HSC structures.