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Elastic wave propagation of ultrasound in bituminous road surfaces - simulations and measurements
(2015)
Elastic wave propagation of ultrasound in bituminous road surfaces – simulations and measurements
(2015)
Maintenance costs of road infrastructure are increasing steadily. Adverse environmental impacts on infrastructure get more and more important as well. Therefore, it is important to determine how limited financial resources can be directed with an optimum pay-out. The present study takes first steps towards the usage of low-frequency ultrasound as a tool to evaluate the road condition.
The special design of buildings, constructed for nuclear power plants is a particular challenge for the nondestructive testing in the building industry. In particular the major component thicknesses, the degree of reinforcement and surface coating systems make the application of NDT methods difficult. The studies first steps were undertaken to determine to which extent established applications of these techniques are useable in the field of infrastructure buildings. Methods have been evaluated that are already state of the art. So for example the ground penetrating radar was used for locating metallic mounting parts. Furthermore, the low-lying internal structure of the containment was investigated with the ultrasonic method.
Elastic wave propagation of ultrasound in bituminous road surfaces - simulations and measurements
(2015)
Maintenance costs of road infrastructure are increasing steadily. The main cause of this is the nearly exponential increase of traffic during the last decades. Adverse environmental impacts on infrastructure get more and more important as well. Therefore, it is important to determine how limited financial resources can be directed with an optimum pay-out. Often a decision has to be made whether existing structures have to be rebuilt or repaired based on the condition of the structures. The present study takes first steps towards the usage of low-frequency ultrasound as a tool to evaluate the road condition. The overall aim is to derive a prediction model for future road conditions. In order to better understand and interpret recorded wave fields simulations of elastic wave propagation in layered and scattering road models have been performed. The study combined investigations in the laboratory with field measurements. In a series of extensive laboratory tests with different asphalt mixtures characteristic wave properties have been derived. Travel time (resp. velocity) as important material parameter has been investigated for different wave types, different centre frequencies and at various temperatures. An investigation of the directivity of wave radiation in the heterogeneous asphalt bodies led to an estimate of the related disturbing influences. Based on the laboratory results field measurements were performed on a real road and the records were processed to identify layers, propagation speeds and attenuation. The results were verified by a series of simulations.
The special design of buildings, constructed for nuclear power plants is a particular challenge for the nondestructive testing in the building industry. In particular the major component thicknesses, the degree of reinforcement and surface coating systems make the application of NDT methods difficult. The studies first steps were undertaken to determine to which extent established applications of these techniques are useable in the field of infrastructure buildings. Methods have been evaluated that are already state of the art. So for example the ground penetrating radar was used for locating metallic mounting parts. Furthermore, the low-lying internal structure of the containment was investigated with the ultrasonic method.