Fast Non-Destructive Localisation of Prestressing Steel Fractures in Post-Tensioned Concrete Bridges

Hillemeier, Bernd; Walther, Andrei

doi:10.1007/978-3-540-72448-3_57

Cited by 5 publications

(5 citation statements)

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“…Moreover, monitoring of the non-accessible parts is a major concern, as those are often considered to be the weakest portions of a structure, where fatigue mechanism and corrosion (due to water ingress/accumulation) tend specifically to prevail. Among the diverse techniques investigated, ultrasonic guided waves (particularly for anchorage zones) [55][56], magnetic flux leakage inspection and acoustic emission monitoring appear to be suitable [57][58]. High-frequency electromagnetic methods (ionizing methods, such as radiography [59][60], or non-ionizing, such as radar or time-domain reflectometry [61]) are also applicable in principle.…”

Section: Ndt Methodsmentioning

confidence: 99%

Some background of monitoring and NDT also useful for timber structures

Kurz

Boller

2015

J Civil Struct Health Monit

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Extension of the life of existing and historic timber structures has increased steadily in the last decade. Sustainability and low carbon emission have influenced activities in the construction industry. In the frame of the European COST Action FP 1101, several activities related to timber structures have been clustered. The COST Action FP 1101 consists of three working groups, namely Assessment (Working Group 1), Reinforcement (Working Group 2) and Monitoring (Working Group 3) of Timber Structures. This special issue of the Journal of Civil Structural Health Monitoring gives an overview of timber structure monitoring activities mainly from a European perspective. This paper is an introduction to this special issue and gives an overview of monitoring concepts and applications related to non-destructive testing (NDT). The prime intention is to give contextual crosslinks to other fields in which NDT methods and monitoring principles have already been developed so that synergies can be realized for timber structures. Outside urgent structural safety issues, monitoring of timber structures has the potential to become a state of the art technology for which material models and NDT-based sensors allow a design criterion for an optimized and highly efficient use of said structures. The sensor concepts may further be enhanced, however, with possible lower cost alternatives in terms of sensors and electronics

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Section: Ndt Methodsmentioning

confidence: 99%

Some background of monitoring and NDT also useful for timber structures

Kurz

Boller

2015

J Civil Struct Health Monit

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“… the different material layers and multiple interfaces of the protection systems (concrete, duct, grout) for the embedded strands configurations  the anchorage zones which concern all bridge technology (cable-suspended, cablestayed, and pre-stressed concrete bridges)  the collar attachments in suspended bridges Moreover, inspection and monitoring of the non-accessible parts is a major concern, as it is often considered as the weakest zones of the structure, where fatigue mechanism and corrosion (due to water ingress/accumulation) exists. Among the diverse investigated techniques, ultrasonic guided waves (particularly for anchorage zones) [8][9], magnetic flux leakage inspection, micromagnetic methods, and acoustic emission monitoring appear to be suitable [10][11]. High-frequency electromagnetic methods (ionizing method as radiography [12][13], or non-ionizing as radar or time-domain reflectometry) were rejected in this case due to the time-consuming nature, radiation hazards and low material portability of the first one, and the screening effect of metallic pieces of the two last ones [14].…”

Section: Background and Ndt Methodsmentioning

confidence: 99%

“…MFL can be applied for inspection of open as well as embedded load carrying elements. By means of MFL the following rope defects can be detected (local faults in terms of wire breaks, pitting corrosion and local abrasion and loss of metallic area due to generalized corrosion or rupture) [16,17]. However, contrary to the surface ones, internal flaws are difficult to detect.…”

Section: Background and Ndt Methodsmentioning

confidence: 99%

NDT for need based maintenance of bridge cables, ropes and pre-stressed elements

Kurz

Laguerre

Niese

et al. 2013

J Civil Struct Health Monit

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This has given life cycle management of infrastructure an increasingly important role. Reliable inspection and monitoring tools are therefore in demand. A reliable prognosis of the condition and behaviour of a structure is an important basis for an effective service life management. Furthermore, traffic loads and loads due to changing environmental conditions increased during the last years and will increase in the future. Repair and maintenance have to be performed, which requires reliable concepts and measurement of data, which is preferably gained through non-destructive methods. Furthermore, infrastructural constructions often have to be reconditioned when they are in use i. e. they cannot be torn down and rebuilt. Therefore, reliable diagnosis of the state of 'hot spots' is required. Within the frame of the Franco-German project FilameNDT steel wires of external tendon ducts and prestressing strands, prestressing rods, and stay cables are investigated. With regards to this field of application, practical relevance can only be gained when easily applicable and long ranging methods are used. The evaluation of extended structural elements using non-contact movable systems {bulk wave and guided wave application [Piezo, electromagnetic acoustic transducers (EMAT)], magnetic flux leakage (MFL), Micromagnetic methods} and those of localized elements based on elastic guided wave propagation are complementary since they can be applied according to the various accessibility conditions of the tested objects. Inspection and monitoring scenarios were developed, hot spots were identified, and lab tests as well as field tests were carried out. A real cable stayed bridge in the Saarland region is available for monitoring within the frame of the project. Results from local investigations using guided waves and from monitoring field tests with micromagnetic sensors are presented and discussed. The results show the scenarios where the non-destructive methods are applicable and how the results can be used for structural health monitoring and maintenance concepts

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“…In contrast, this study, as with many other previously published studies in the field of SHM (e.g., Hillemeier and Walther, ), uses the time course of real defects that have been monitored and their EMAD data collected over a 12‐month period. One disadvantage of using an experimental approach in this case is that defects take time to develop, decades in some cases, requiring the use of corrosion acceleration measures.…”

Section: Investigative Case Studiesmentioning

confidence: 99%

“…Similar techniques to the EMAD approach have been previously investigated. For example, the approach reported by Hillemeier and Walther () used MFL for the detection of breaks within rebars. MFL‐based techniques have also been extensively used in the pipeline industry where “pipeline pigs” are typically used to detect corrosion and loss of section in oil and gas pipelines (e.g., Babbar and Clapham, ; Li et al., ).…”

Section: Introductionmentioning

confidence: 99%

Defect Detection in Reinforced Concrete Using Random Neural Architectures

Butcher

Day

Austin

et al. 2013

Computer aided Civil Eng

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Detecting defects within reinforced concrete is vital to the safety and durability of our built infrastructure upon which we heavily rely. In this work a noninvasive technique, ElectroMagnetic Anomaly Detection (EMAD), is used which provides information into the electromagnetic properties of the reinforcing steel and for which data analysis is currently performed visually: an undesirable process. This article investigates the first use of two neural network approaches to automate the analysis of this data: Echo State Networks (ESNs) and Extreme Learning Machines (ELMs) where fast and efficient training procedures allow networks to be trained and evaluated in less time than traditional neural network approaches. Data collected from real-world concrete structures have been analyzed using these two approaches as well as using a simple threshold measure and a standard recurrent neural network. The ELM approach offers a significant improvement in performance for a single tendon-reinforced structure, while two ESN architectures provided best performance for a meshreinforced concrete structure. C 2013 Computer-Aided Civil and Infrastructure Engineering.

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Fast Non-Destructive Localisation of Prestressing Steel Fractures in Post-Tensioned Concrete Bridges

Cited by 5 publications

References 1 publication

Some background of monitoring and NDT also useful for timber structures

Some background of monitoring and NDT also useful for timber structures

NDT for need based maintenance of bridge cables, ropes and pre-stressed elements

Defect Detection in Reinforced Concrete Using Random Neural Architectures

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