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Embedded ultrasonic transducers for active and passive concrete monitoring.

Niederleithinger E, Wolf J, Mielentz F, Wiggenhauser H, Pirskawetz S - Sensors (Basel) (2015)

Bottom Line: The transducer design, the main properties as well as installation procedures are presented.Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, …) as well as damages in an early state or the detection of acoustic events (e.g., crack opening).Besides application in civil engineering our setups can also be used for model studies in geosciences.

View Article: PubMed Central - PubMed

Affiliation: BAM Federal Institute for Materials Research and Testing, Berlin 12200, Germany. ernst.niederleithinger@bam.de.

ABSTRACT
Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well as installation procedures are presented. It is shown that compressional waves with a central frequency of 62 kHz are mainly generated around the transducer's axis. The transducer can be used as a transmitter or receiver. Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, …) as well as damages in an early state or the detection of acoustic events (e.g., crack opening). Besides application in civil engineering our setups can also be used for model studies in geosciences.

No MeSH data available.


Related in: MedlinePlus

Correlation coefficient of 5 ms time series (reference: measurement at zero load) of ultrasonic signals measured by embedded transducers in a concrete block under small local compressional load. Line represents very dense consecutive measurements. From [26].
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sensors-15-09756-f011: Correlation coefficient of 5 ms time series (reference: measurement at zero load) of ultrasonic signals measured by embedded transducers in a concrete block under small local compressional load. Line represents very dense consecutive measurements. From [26].

Mentions: The applied loads, even very small ones, had a clear influence on the ultrasonic signals. A simple but valuable tool to provide a measure for the change is calculating the correlation coefficient between a reference measurement (here: zero load) and all consecutive measurement under various load conditions. Figure 11 shows the development of the correlations coefficient for transmission data between two embedded transducers close to the loading point. Both transducers have the same embedment depth (seen from the front face). Thus, direct waves are traveling perpendicular to the main load direction, but later parts of the signals (reflections, scattering) contain also information from different propagation directions.


Embedded ultrasonic transducers for active and passive concrete monitoring.

Niederleithinger E, Wolf J, Mielentz F, Wiggenhauser H, Pirskawetz S - Sensors (Basel) (2015)

Correlation coefficient of 5 ms time series (reference: measurement at zero load) of ultrasonic signals measured by embedded transducers in a concrete block under small local compressional load. Line represents very dense consecutive measurements. From [26].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4481983&req=5

sensors-15-09756-f011: Correlation coefficient of 5 ms time series (reference: measurement at zero load) of ultrasonic signals measured by embedded transducers in a concrete block under small local compressional load. Line represents very dense consecutive measurements. From [26].
Mentions: The applied loads, even very small ones, had a clear influence on the ultrasonic signals. A simple but valuable tool to provide a measure for the change is calculating the correlation coefficient between a reference measurement (here: zero load) and all consecutive measurement under various load conditions. Figure 11 shows the development of the correlations coefficient for transmission data between two embedded transducers close to the loading point. Both transducers have the same embedment depth (seen from the front face). Thus, direct waves are traveling perpendicular to the main load direction, but later parts of the signals (reflections, scattering) contain also information from different propagation directions.

Bottom Line: The transducer design, the main properties as well as installation procedures are presented.Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, …) as well as damages in an early state or the detection of acoustic events (e.g., crack opening).Besides application in civil engineering our setups can also be used for model studies in geosciences.

View Article: PubMed Central - PubMed

Affiliation: BAM Federal Institute for Materials Research and Testing, Berlin 12200, Germany. ernst.niederleithinger@bam.de.

ABSTRACT
Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well as installation procedures are presented. It is shown that compressional waves with a central frequency of 62 kHz are mainly generated around the transducer's axis. The transducer can be used as a transmitter or receiver. Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, …) as well as damages in an early state or the detection of acoustic events (e.g., crack opening). Besides application in civil engineering our setups can also be used for model studies in geosciences.

No MeSH data available.


Related in: MedlinePlus