Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Improper filled ducts detected by ultrasound reflections
Results of investigations performed at specimens prepared by BAM, Berlin, BASt, Bergisch-Gladbach and Darmstadt Technical University, which contain partially filled tendon ducts are presented. These specimens differ in the used concrete mixture and in the content of ordinary reinforcement. The measurements were taken utilising the pin contact shear wave ultrasound transducer array A1220 which is manufactured by MSIA Spectrum, Moscow. It is the aim of the investigations to check the capability of the applied technique to find areas of the ducts which are unfilled with grout. Therefore statistical techniques evaluating the amplitude of the back scattered ultrasonic signals are applied. These techniques were developed and tested in former investigations. The differences in the reflectivity of filled and unfilled ducts embedded in concrete with up to a thickness of 70 cm with different percentages and arrangements of ordinary reinforcement proved to be detectable by shear wave reflection technique. Statistical evaluation of amplitudes obtained by the measurements indicate that it can be distinguished between plain concrete, filled and unfilled duct. Refining these observations by introduction of other better suited probability density functions in the sense of and estimating the thresholds by means of improved techniques will be the next step of our research work.
Improper filled ducts detected by ultrasound reflections
Results of investigations performed at specimens prepared by BAM, Berlin, BASt, Bergisch-Gladbach and Darmstadt Technical University, which contain partially filled tendon ducts are presented. These specimens differ in the used concrete mixture and in the content of ordinary reinforcement. The measurements were taken utilising the pin contact shear wave ultrasound transducer array A1220 which is manufactured by MSIA Spectrum, Moscow. It is the aim of the investigations to check the capability of the applied technique to find areas of the ducts which are unfilled with grout. Therefore statistical techniques evaluating the amplitude of the back scattered ultrasonic signals are applied. These techniques were developed and tested in former investigations. The differences in the reflectivity of filled and unfilled ducts embedded in concrete with up to a thickness of 70 cm with different percentages and arrangements of ordinary reinforcement proved to be detectable by shear wave reflection technique. Statistical evaluation of amplitudes obtained by the measurements indicate that it can be distinguished between plain concrete, filled and unfilled duct. Refining these observations by introduction of other better suited probability density functions in the sense of and estimating the thresholds by means of improved techniques will be the next step of our research work.
Improper filled ducts detected by ultrasound reflections
Nachweis ungenau gefüllter Kanäle durch Ultraschallreflexion
Jansohn, R. (Autor:in) / Scherzer, J. (Autor:in)
2002
11 Seiten, 13 Bilder, 13 Quellen
(Nicht paginiert).
Aufsatz (Konferenz)
Datenträger
Englisch
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