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- Ultraschallecho (5)
- Ultrasonic echo (5)
- SAFT (4)
- Concrete (3)
- Reconstruction calculation (3)
- Spannbeton (3)
- Spannkanäle (3)
- Verpressfehler (3)
- Modellierung (2)
- Non-destructive testing (2)
- Prestressed concrete structures (2)
- Radar (2)
- Rekonstruktionsrechnung (2)
- Ultrasonic imaging (2)
- Ultrasound (2)
- Zerstörungsfreie Prüfung (2)
- 3D-SAFT (1)
- Acoustic test (1)
- Air-coupled ultrasound (1)
- Array technique (1)
- Asphalt (1)
- Bauen im Bestand (1)
- Beton (1)
- Betonbauteile (1)
- Brücken (1)
- Commercial acoustic devices (1)
- Concrete bridge (1)
- Concrete specimens (1)
- Crack depth (1)
- Dickenmessung (1)
- EFIT (1)
- EFIT Modelling (1)
- EFIT modelling (1)
- EFIT-modeling (1)
- Elastodynamic Finite Integration Technique (EFIT) (1)
- Embedded sensor (1)
- FT-SAFT (1)
- Flaw characterization (1)
- Grouting condition (1)
- Hohlraumgehalt (1)
- Hüllrohr (1)
- Imaging (1)
- Impact-echo (1)
- Impakt-Echo-Messverfahren (1)
- Impuls-Radar-Messverfahren (1)
- Kosteneinsparung (1)
- Leerrohre (1)
- Luftgekoppelter Ultraschall (1)
- Modeling (EFIT) (1)
- Modellierung elastischer Wellen (1)
- Monitoring (1)
- Monitoring system (1)
- NDT (1)
- Phase analysis (1)
- Phase evaluation (1)
- Phased Array (1)
- Phased array (1)
- Polarimetrische Abbildungsverfahren (1)
- Post-tensioned concrete (1)
- Prestressed concrete bridges (1)
- Prestressing ducts (1)
- Radarverfahren (1)
- Reinforced concrete (1)
- SAFT (Synthetic Aperture Focusing Technique) (1)
- Sohlplatte (1)
- Tendon duct (1)
- Tendon ducts (1)
- Tendons (1)
- Tunnels (1)
- Ultraschall-Array-Messverfahren (1)
- Ultraschall-Echo-Verfahren (1)
- Ultraschall-Rückstreuung (1)
- Ultraschallecho-Verfahren (1)
- Ultraschallverfahren (1)
- Ultrasonic (1)
- Ultrasonic network (1)
- Ultrasonic test (1)
- Zerstörungsfreie Prüfung im Bauwesen (1)
- Zerstörungsfreie Prüfung im Bauwesen (ZfPBau) (1)
- ZfP-Bau (1)
- ZfPBau (1)
Cracks perpendicular to the surface may be initial indicators for a deterioration process of concrete structures. Moisture penetrates inside the structure and transports adverse chemicals. The paper presents an investigation about the reliability of available commercial non-destructive evaluation techniques to reliably estimate the depth of surface-breaking cracks in reinforced concrete structures. Aim of the study was the investigation of surface-braking cracks under laboratory conditions. Commercial acoustic devices as impact echo equipment, single ultrasonic transducers and arrays were applied even if they have not been developed for this purpose. The commercial software and descriptions for application was followed strictly to compare the function, precision and repeatability of the measurements. Both, perpendicular notches and cracks have been considered. The study was completed with a discussion about reference specimens. The study was the basis for formulation of gaps in research. The Electric Power Research Institute (EPRI) has initiated and funded a Project.
In Zeiten knapper Kassen wird überall nach Wegen gesucht Kosten einzusparen. Im Bauwesen geht es dabei um Kosteneinsparungen ohne Reduktion der Sicherheit und Dauerhaftigkeit des Bauwerks. Beim Bauen im Bestand können mit einer zerstörungsfreien Prüfung von Bauwerken die Weiternutzung oder die erforderlichen Umbauten optimiert werden und so Kosten eingespart werden.
Ultrasonic imaging of tendon ducts enables the precise localisation of grouting faults in many cases. Additionally to well known criteria for detecting grouting faults in tendon ducts recently new possibilities were developed. Two main effects influence the complex behaviour of wave propagation and reflection: a) different arrangement and number of strands or internal rebars; b) superposition of reflecting signals and different wave modes propagating into the interface region around the tendon duct. In order to understand the experimental results, EFIT modelling is performed (EFIT: Elastodynamic Finite Integration Technique).