Ultrasonic coda wave monitoring of concrete structures: First experiences with large-scale experiments and real structures

A Review of Approaches for Mitigating Effects from Variable Operational Environments on Piezoelectric Transducers for Long-Term Structural Health Monitoring

“…It is hence recommended to set-up data acquisition, data storage, and analysis equipment for SHM performed outdoors in a cabin or container providing protection against environmental effects and limiting access to authorized personnel, as discussed, e.g., by [42]. After the publication of the review [32], additional examples of long-term SHM were found, see, e.g., [43][44][45]. Examples of commercial bridge monitoring in Germany, running up to six years now (Thalaubachtal Bridge since 2017) are noted in a summary presentation (in German) at a technical meeting [46].…”

“…However, this does not necessarily mean that none occurred. Publishing documented company internal problem reports on damage or failure of all components of SHM systems, as well as systematically After the publication of the review [32], additional examples of long-term SHM were found, see, e.g., [43][44][45]. Examples of commercial bridge monitoring in Germany, running up to six years now (Thalaubachtal Bridge since 2017) are noted in a summary presentation (in German) at a technical meeting [46].…”

Combining Active and Passive Stress Wave Monitoring Techniques: Opportunities for Condition Assessment of Concrete Structures

“…Additionally, AE can be used during the structural load testing of in-service bridges, providing useful information regarding load-level and cracking [3,4]. Separately, active ultrasonic stress wave (USW) monitoring has been explored recently to monitor loading of and deterioration processes in real structures [5,6]. While AE monitoring can capture ongoing internal fracture processes such as cracking, reinforcement-concrete interaction, and reinforcement fracture, USW monitoring, in particular combined with coda wave analysis, can document minute and slowly varying condition changes from, e.g., temperature variation [7], changes in the stress field due to service-level loads [8], and degradation processes [5].…”

“…Separately, active ultrasonic stress wave (USW) monitoring has been explored recently to monitor loading of and deterioration processes in real structures [5,6]. While AE monitoring can capture ongoing internal fracture processes such as cracking, reinforcement-concrete interaction, and reinforcement fracture, USW monitoring, in particular combined with coda wave analysis, can document minute and slowly varying condition changes from, e.g., temperature variation [7], changes in the stress field due to service-level loads [8], and degradation processes [5]. Both methods show potential to provide quantitative measures for changes in structures and materials, e. g., for fatigue [9,10].…”

“…Select analyses b-Value analysis [21], Historicseverity analysis [22], Source localization [19], Moment tensor inversion (MTI) [23] p-Wave velocity (cp), s-Wave velocity (cs), Magnitude-squared coherence (MSC) [8], Coda wave interferometry (CWI) [24] Detection abilities Micro-and macro-cracking of concrete, rebar-concrete interaction, reinforcement/tendon wire fracture [1,2] Temperature variations [7], stress variations due to service-level loads [25], alkali-silica reaction (ASR) (only in laboratory setting) [26], rebar corrosion (only in laboratory setting) [27] Select reported applications on real structures Monitoring of prestressing wire breaks [1,2] Condition monitoring of a highway bridge [5], Monitoring of damage progression of an ASR-damaged structure [5] NDT-CE 2022 -The International Symposium on Nondestructive Testing in Civil Engineering Zurich, Switzerland, August 16-18, 2022 4…”