PSI - Issue 64

Victor Procópio de Oliveira et al. / Procedia Structural Integrity 64 (2024) 653–660 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

657

5

Pulsed Eddy Current Test (PEC)

Advanced NDT technique for inspecting conductive materials like metals, detecting corrosion, thickness loss, and other discontinuities. Application: Identification of corrosion and material degradation, evaluation of structural integrity of bridges and other civil structures, research and development of materials. Evaluates the corrosion state of reinforcement in reinforced concrete structures. Application: Inspection of bridges, viaducts, and other reinforced concrete structures for early problem detection.

Tied to the amount of data collected and frequency and density of measurement points. Systematic and well planned positioning to ensure comprehensive inspection coverage. Application and extension of technique in various inspection scenarios of reinforced concrete structures. Proper positioning of reference electrode to obtain accurate measurements, covering different exposure conditions.

Pulse generator sends magnetic field through material; sensor detects response, varying by thickness and discontinuities. Analytics software processes data with filters and algorithms, presenting results as graphs and thickness maps. Measurements taken at various points to assess uniformity of corrosion potential. Data analyzed using dedicated software with filters and algorithms, presented as graphs and potential maps.

Temperature, humidity, and other conditions, requiring equipment calibration for specific conditions. Humidity, surface contamination, temperature, marine environments, air pollution, carbonation presence, and

Ha, Lee, Lee, (2021). Eddy, Underhill,

Krause, (2020).

Half-Cell Potential Test

Dasar, Patah, Apriansyah, (2022).

direct sun exposure.

3 Smart Sensors for SHM Sivasuriyan (2021) notes that the utilization of intelligent sensors for observing structural integrity in reinforced concrete structures has a comparatively new history, starting in the 1990s. The initial smart sensors relied on electromechanical technologies, such as strain and temperature sensors. While these sensors could collect data on the structural condition, they had limitations in detecting damage. In today's construction and engineering practices, various smart sensors are employed to monitor the health and integrity of structures. These sensors utilize cutting-edge technologies, including wireless connectivity, advanced data analytics, real-time monitoring capabilities, and enabling more proactive maintenance strategies. By analysing collected data, these sensors allow for the prediction and planning of intervention measures to address structural damage, optimizing resources and reducing waste generation. As suggested by Haque (2020), this proactive maintenance approach can significantly increase the service life and durability of civil structures. Some of the smart sensors used in modern construction are described. Capacitive accelerometers with microelectromechanical systems (MEMS), as described by Liu (2022), are microscopic devices with moving parts that effectively meet modern Structural Health Monitoring demands. These accelerometers measure both constant and dynamic accelerations using a capacitive acceleration sensor connected to an electrical circuit, which converts the measurements into voltage outputs. Constant acceleration, caused by gravitational force, helps determine the device's angle of inclination relative to Earth's gravitational vector, similar to the orientation adjustment in smartphones. Dynamic acceleration results from vibrations and movements, allowing these accelerometers to track the direction and velocity of movements in structures, such as reinforced and prestressed concrete, and log any impacts. Figure 2a in Liu's study illustrates the practical application of these accelerometers in Structural Health Monitoring. Tiltmeters, as described by Zhuang et al (2020), are sensitive inclinometers designed to measure very small changes from the vertical level, either in the ground or in reinforced concrete structures. Tiltmeters are also widely used to monitor volcanoes, the reaction of dams to fill, subtle signals of movements associated with potential landslides, and the response of structures to various influences such as loads and accommodations on foundations (ZHUANG et al. 2020). Figure 2b shows a tiltmeter installed at the Fengman Dam, used to measure movements according to water level variation. The Fengman Dam is a concrete gravity dam located 20 km from the city of Jilin, China, whose main purpose is to generate hydroelectric power and control floods in the regions downstream of the structure. These devices can be fully mechanical or incorporate vibrating wire or electrolytic sensors to perform electronic measurements. A high sensitivity tiltmeter can identify changes as small as one arcsecond.