Ultraschalluntersuchungen an statisch beanspruchten Betonproben

Ultrasonic investigations on compressive stressed concrete specimen

Ultrasonic measurement methods are already offering in various scientific disciplines (e.g. medicine, biology) an enormous performance potential. But also in other construction-related sectors (e.g. steel construction, natural stone test) or in the field of geosciences the ultrasonic measurement technology is used successfully and multiple. In contrast the application in concrete construction is clearly underdeveloped, but especially laboratory tests show that it is ideally suitable for condition assessment and damage observation.
In this paper results are presented of ultrasonic transmission time measurements of compressive loaded concrete specimens. The results were collected as part of a literature study and supplemented by own investigations. The investigations were performed at a normal strength concrete in force- and stroke controlled compression tests. It is shown that the crack formation by increasing compressive stresses leads to a significant decrease in the ultrasonic pulse velocity. In addition, it was found that the fracture of the specimen is indicated by the change in ultrasonic pulse velocity substantially clearly than can be read in a stress-strain curve.