A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Fast location of prestressing steel fractures in bridge decks and parking lots
The measuring speed of the Remanent Magnetism Method (RM-Method) can be enhanced significantly by replacing the time-consuming multi-step-magnetization by a single-step-magnetization. The RM-Method allows identification of potentially unsafe conditions in pre-tensioned and post-tensioned concrete structures by locating fractures of single wires, even if they are bundled with intact wires. Once they have been pre-magnetized with an electromagnet, the magnetic field of tendons is measured at the concrete surface. Fractures produce characteristic magnetic leakage fields, which can be measured with appropriate sensors at the concrete surface. Large yoke-shaped magnets have been constructed to magnetize transverse tendons in bridge decks of lengths up to 4m in a single process. Measuring the magnetic flux density of an entire bridge deck simplifies the comparison of data from measurements at different times, which would be helpful for the monitoring of the structure. The feasibility of rapid magnetization of tendons using an appropriate electromagnetic yoke was shown in laboratory tests. Furthermore, data acquisition and interpretation are of no general difficulty. At present, a vehicle to drive the measurement devices is being developed. This work is to be completed by spring 2004. With this a fast procedure for locating prestressing steel fractures in transverse tendons of bridge decks or tendons other plane structures, such as parking decks, would become available. The measuring speed would be increased by several magnitudes. As a result, structural testing of the prestressing steel, required to maintain structural safety, could be performed without severe disruption of traffic.
Fast location of prestressing steel fractures in bridge decks and parking lots
The measuring speed of the Remanent Magnetism Method (RM-Method) can be enhanced significantly by replacing the time-consuming multi-step-magnetization by a single-step-magnetization. The RM-Method allows identification of potentially unsafe conditions in pre-tensioned and post-tensioned concrete structures by locating fractures of single wires, even if they are bundled with intact wires. Once they have been pre-magnetized with an electromagnet, the magnetic field of tendons is measured at the concrete surface. Fractures produce characteristic magnetic leakage fields, which can be measured with appropriate sensors at the concrete surface. Large yoke-shaped magnets have been constructed to magnetize transverse tendons in bridge decks of lengths up to 4m in a single process. Measuring the magnetic flux density of an entire bridge deck simplifies the comparison of data from measurements at different times, which would be helpful for the monitoring of the structure. The feasibility of rapid magnetization of tendons using an appropriate electromagnetic yoke was shown in laboratory tests. Furthermore, data acquisition and interpretation are of no general difficulty. At present, a vehicle to drive the measurement devices is being developed. This work is to be completed by spring 2004. With this a fast procedure for locating prestressing steel fractures in transverse tendons of bridge decks or tendons other plane structures, such as parking decks, would become available. The measuring speed would be increased by several magnitudes. As a result, structural testing of the prestressing steel, required to maintain structural safety, could be performed without severe disruption of traffic.
Fast location of prestressing steel fractures in bridge decks and parking lots
Schnelle Ortung vorgespannter Stahlfrakturen in Brückenbelägen und Parkplattformen
Scheel, H. (author) / Hillemeier, B. (author)
2003
6 Seiten, 2 Bilder, 5 Quellen
(Nicht paginiert)
Conference paper
Storage medium
English
External prestressing and unbonded tendons in bridge decks
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Location of Prestressing Steel Fractures in Concrete
| British Library Online Contents | 2003
Location of Prestressing Steel Fractures in Concrete
| Online Contents | 2003