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Ultrasound through-transmission techniques for quality control of concrete during setting and hardening
Based on ultrasound soft- and hardware called FreshCon (for concrete materials) or FreshMor (for mortar) a device was developed at the Stuttgart University to investigate cementitious materials in regard to their quality, workability and setting and hardening. The implemented analysis techniques are applied using the whole waveform representing material properties. However, for quantitative analysis techniques some parameters could be extracted out of the signals recorded by this measuring device. Elastic parameters that are suitable to be used for this approach are the velocity, the energy and the frequency content. Recently, a new feature of the FreshCon system, the ability to record the temperature evolution over time, was introduced as well as the determination of the associated hydration heat. There are several other parameters that can be used also. Even though one single wave parameter could be sufficient to characterize the material, the reliability of the method is increased by evaluating more than one. For a rapid first interpretation of material properties the determination of the initial and final setting time was implemented. A more sophisticated data condensing can be achieved using the Boltzmann function. Comparing the graphs of different material compositions differences in quality as well as of the workability can be found. Applications address investigations of material parameters like the water-to-cementratio, the type of cement or the effect of additives as retarders or accelerators. At the concreting site, where efficiency and a low budget are boundary conditions, the application of this new technique can help to enhance the stability during construction or the progress of the construction work saving both: time and money. Some examples are the development of admixtures, the in-situ quality control, the slip form concreting or the precasting. Certainly, the applications are not restricted to cementitious materials.
Ultrasound through-transmission techniques for quality control of concrete during setting and hardening
Based on ultrasound soft- and hardware called FreshCon (for concrete materials) or FreshMor (for mortar) a device was developed at the Stuttgart University to investigate cementitious materials in regard to their quality, workability and setting and hardening. The implemented analysis techniques are applied using the whole waveform representing material properties. However, for quantitative analysis techniques some parameters could be extracted out of the signals recorded by this measuring device. Elastic parameters that are suitable to be used for this approach are the velocity, the energy and the frequency content. Recently, a new feature of the FreshCon system, the ability to record the temperature evolution over time, was introduced as well as the determination of the associated hydration heat. There are several other parameters that can be used also. Even though one single wave parameter could be sufficient to characterize the material, the reliability of the method is increased by evaluating more than one. For a rapid first interpretation of material properties the determination of the initial and final setting time was implemented. A more sophisticated data condensing can be achieved using the Boltzmann function. Comparing the graphs of different material compositions differences in quality as well as of the workability can be found. Applications address investigations of material parameters like the water-to-cementratio, the type of cement or the effect of additives as retarders or accelerators. At the concreting site, where efficiency and a low budget are boundary conditions, the application of this new technique can help to enhance the stability during construction or the progress of the construction work saving both: time and money. Some examples are the development of admixtures, the in-situ quality control, the slip form concreting or the precasting. Certainly, the applications are not restricted to cementitious materials.
Ultrasound through-transmission techniques for quality control of concrete during setting and hardening
Ultraschall-Durchschallungsverfahren zur Qualitätskontrolle von Beton beim Abbinden und Aushärten
Grosse, C.U. (author) / Reinhardt, H.W. (author) / Krüger, M. (author) / Beutel, R. (author)
2006
11 Seiten, 9 Bilder, 16 Quellen
Conference paper
Storage medium
English
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