GPR inspection of concrete bridges Hugenschmidt, Johannes; Mastrangelo, Roman
Cement & concrete composites,
04/2006, Letnik:
28, Številka:
4
Journal Article
Recenzirano
Ground-penetrating-radar (GPR) has become an important method for the non-destructive testing of concrete bridges. Although there are standards and guidelines available today, the quality of results ...does not only depend on the object inspected but also on the qualification and experience of the team carrying out the radar survey. This situation is unsatisfactory for engineers that have to decide whether a radar survey is suitable to solve their problem.
EMPA has been active in the field of non-destructive testing of concrete structures for more than ten years. During this time, procedures for efficient data acquisition, processing interpretation and reporting have been developed. In addition, a large number of concrete structures has been inspected for research and services.
In a research project completed in 2005, radar inspections using the EMPA approach were carried out on bridges designated for demolition. Results were laid open before the bridges were taken down. After the demolition radar results were verified with the help of the bridge parts. Thus, the accuracy and reliability of radar surveys was quantified under realistic circumstances.
Processing strategies for high-resolution GPR concrete inspections Hugenschmidt, Johannes; Kalogeropoulos, Alexis; Soldovieri, Francesco ...
NDT & E international : independent nondestructive testing and evaluation,
06/2010, Letnik:
43, Številka:
4
Journal Article
Recenzirano
A high-resolution multi-sensor and multi-polarization Ground Penetrating Radar (GPR) dataset was acquired on a concrete retaining wall. This dataset was characterised as a low pass filter with the ...help of a moving window spectral analysis. In order to examine the benefits and limits of innovative processing strategies, the dataset was processed with three different methods: classical 2-D processing, full 3-D processing followed by data fusion and inverse scattering followed by data fusion. A comparison of the results for two layers of rebar present in the wall shows that the innovative approaches improve the results for near surface structures when compared to classical 2-D processing. For deeper structures, the benefits of the innovative approaches are limited because of the low pass properties of the concrete.
Mittels Radaruntersuchungen werden Betondeckenbereiche einer Fläche von 2 × 0,9 m2 in Stützennähe in ausgewählten Einstellhallen zerstörungsfrei mit dem Ziel untersucht, typische Bewehrungselemente ...zur Erhöhung des Durchstanzwiderstands zu erkennen. Im Untersuchungsergebnis zeigte sich, dass diese Elemente, wie z.B. Bewehrungsstäbe, Stahlpilze oder Dübelleisten, mit hoher Wahrscheinlichkeit identifiziert werden können. Die Messdaten liefern für die meisten untersuchten Elementtypen spezifische, reproduzierbare Datenmuster. Mithilfe von Radaruntersuchungen ist es deshalb möglich, auf nicht dokumentierte Bewehrungselemente im Bauwerk zu schließen. Die Bauingenieure können so den Durchstanzwiderstand von Flachdecken im Bereich ihrer Stützen besser beurteilen. Das eröffnet Prüfmöglichkeiten zur Durchstanzproblematik in Bezug auf die Einhaltung technisch verbindlicher Normen sowie zur Untersuchung von Bauschäden oder deren Prophylaxe.
Non‐destructive inspection of punching shear reinforcement in concrete flat slabs
In selected car parks, ground penetrating radar (GPR) surveys were carried out on ceiling areas in the vicinity of piles. The areas inspected were 0.9 m × 2.0 m each. The aim of the surveys was the detection Punching shear reinforcement (PSR). It was shown that several types of PSR can be detected reliably. The acquired GPR data show distinctive reflection patterns for most types of PSR. It is therefore possible to detect punching shear reinforcement in cases where appropriate documentation of the construction details is missing. Thus, GPR surveys can provide information relevant for the engineer for assessing the safety of buildings. This facilitates testing options related to the punching problem. Objects can be tested for compliance with existing standards, for the evaluation of structural damage or for prevention.
ABSTRACT
Industrial railway tracks are important for the loading and unloading of goods and therefore for the railway system in general. Often, industrial tracks are embedded in concrete and/or ...asphalt to enable trucks and other traffic across rails. Thus, most of the construction is hidden from visual inspection. If repair work is planned or if damage occurs, details of the construction have to be known for the planning of repair work and for the evaluation of damages. This paper describes the characteristics of industrial railway tracks, frequent problems and the non‐destructive testing on several real sites using GPR. Typical testing problems, most of them related to construction details, are described and the application of GPR for these problems is demonstrated using data from field measurements. Data from different types of equipment are compared and benefits and limits of the method are discussed. It is shown that GPR can provide information that is required to address problems that can be found frequently on industrial railway track sites.
The ISTIMES project, funded by the European Commission in the frame of a joint Call "ICT and Security" of the Seventh Framework Programme, is presented and preliminary research results are discussed. ...The main objective of the ISTIMES project is to design, assess and promote an Information and Communication Technologies (ICT)-based system, exploiting distributed and local sensors, for non-destructive electromagnetic monitoring of critical transport infrastructures. The integration of electromagnetic technologies with new ICT information and telecommunications systems enables remotely controlled monitoring and surveillance and real time data imaging of the critical transport infrastructures. The project exploits different non-invasive imaging technologies based on electromagnetic sensing (optic fiber sensors, Synthetic Aperture Radar satellite platform based, hyperspectral spectroscopy, Infrared thermography, Ground Penetrating Radar-, low-frequency geophysical techniques, Ground based systems for displacement monitoring). In this paper, we show the preliminary results arising from the GPR and infrared thermographic measurements carried out on the Musmeci bridge in Potenza, located in a highly seismic area of the Apennine chain (Southern Italy) and representing one of the test beds of the project.
Remains of pile dwellings are present in many lakes around the Alps, particularly north of the Alps in Germany, Austria and Switzerland. Those remains originating from 5000-1000 B.C. are listed as ...UNESCO World Heritage because of their historical and cultural importance and thus, deserve protection. On the known pile dwelling site of Freienbach-Hurden/Seefeld in Lake Zurich near Rapperswil, Switzerland several investigations were carried out to map and characterize the cultural layers. Amongst other inspections a GPR survey was carried out. Data were acquired in shallow water with a boat, processed and interpreted with the help of drilling information. The final results was a 3-D model of cultural layers which can now be used for the planning of protective measures.
PDF
