TY - CONF A1 - Küttenbaum, Stefan A1 - Taffe, A. A1 - Braml, T. A1 - Maack, Stefan ED - Alexander, M. G. ED - Beushausen, H. ED - Dehn, F. ED - Moyo, P. T1 - Reliability assessment of existing bridge constructions based on results of non-destructive testing T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2018) N2 - The non-destructive testing methods available for civil engineering (NDT-CE) enable the measurements of quantitative parameters, which realistically describe the characteristics of existing buildings. In the past, methods for quality evaluation and concepts for validation expanded into NDT-CE to improve the objectivity of measured data. Thereby, a metrological foundation was developed to collect statistically sound and structurally relevant information about the inner construction of structures without destructive interventions. More recently, the demand for recalculations of structural safety was identified. This paper summarizes a basic research study on structural analyses of bridges in combination with NDT. The aim is to use measurement data of nondestructive testing methods as stochastic quantities in static calculations. Therefore, a methodical interface between the guide to the expression of uncertainty in measurement and probabilistic approximation procedures (e.g. FORM) has been proven to be suitable. The motivation is to relate the scientific approach of the structural analysis with real information coming from existing structures and not with those found in the literature. A case study about the probabilistic bending proof of a reinforced concrete bridge with statistically verified data from ultrasonic measurements shows that the measuring results fulfil the requirements concerning precision, trueness, objectivity and reliability. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2018) CY - Cape Town, South Africa DA - 19.11.2018 KW - NDT KW - Concrete KW - Probabilistic reassessment KW - Bridge PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-467898 DO - https://doi.org/10.1051/matecconf/201819906001 SN - 2261-236X VL - 199 SP - 06001, 1 EP - 9 PB - MATEC Web of Conferences AN - OPUS4-46789 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan A1 - Villalobos, S. A1 - Scott, D. T1 - Validation of artificial defects for non-destructive testing measurements on a reference structure T2 - MATEC web of conferences N2 - Non-destructive testing was established over the last decades as an important tool for assessing damages, material characterization and quality assurance in civil engineering. For example, Ground Penetrating Radar (GPR) can be used to scan large areas of concrete structures to determine the spatial position of the reinforcement. With the ultrasonic echo method, the thickness of concrete structures can be easily determined even if a high density of reinforcement is given. Various methods and processes have been developed for the validation of NDT procedures aiming at ensuring the quality of measurements in practical use. The Probability of Detection (POD) for example, is an available method to compare different technical devices with each other quantitatively regarding their performance. With this method, the best suited testing device for a specific inspection task under defined boundary conditions can be selected. By using the Guide to the Expression of Uncertainty in Measurement (GUM), it is possible to quantify the measurement uncertainty of an inspection procedure for a specific task. Another important aspect to improve the acceptance of Non-destructive testing methods is the development of reference specimens. Reference specimens serve for the calibration and further development of NDT methods under realistic conditions in different laboratories under the same conditions. A particular challenge here is the most realistic representation of a damage that can occur at building sites. Possible damages include for example horizontal and vertical cracks or honeycombs in concrete. Such a reference structure was built for the development of a new design of power plant constructions. Comparative studies on the manufacturing of realistic honeycombs and delaminations were carried out in advance on a test specimen. The results of this study are presented here. T2 - ICCRRR 2018 - Concrete Repair, Rehabilitation and Retrofitting CY - Cape Town, South Africa DA - 19.11.2018 KW - Zerstörungsfreie Prüfung KW - Nondestructive testing KW - Istzustandserfassung KW - Ultrasonic PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-464497 DO - https://doi.org/10.1051/matecconf/201819906006 SN - 2261-236X VL - 199 SP - 1 EP - 9 PB - EDP Sciences CY - Les Ulis AN - OPUS4-46449 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Küttenbaum, Stefan A1 - Maack, Stefan A1 - Taffe, A. T1 - Structural safety referring to ultrasound on concrete bridges JF - Beton- und Stahlbetonbau N2 - Measuring means knowing. The structural engineer’s Knowledge about structures is vitally important for the assessment of their structural safety. This contribution shows, how non-destructive testing methods can be used to collect valuable Information about existing structures. This value is expressed in this paper by the usability in probabilistic assessments and thus by the reliability of the information. The development of non-destructive testing methods in civil-engineering allows the realistic measurement and visualization of inner constructions of concrete components with a minimum of destructive interventions. The evaluation of the quality of measurement data is of fundamental importance for quantitative measurements in order to ensure the objectivity of testing and evaluation and to assess the reliability of the knowledge acquired. Both systematic and random deviations must be identified, quantified and taken into account to obtain statistically sound data. The Focus of this contribution is on the methodical path, how displayed measurement data can be processed into reliable knowledge. It is not about developing assessment methods but about providing necessary knowledge to increase their operational usability. T2 - 16th International Probabilistic Workshop CY - Vienna, Austria DA - 12.09.2018 KW - NDT KW - Reassessment KW - Probabilistic KW - Non-destructive testing in civil engineering PY - 2018 DO - https://doi.org/10.1002/best.201800034 SN - 1437-1006 VL - 113 IS - S2 SP - 7 EP - 13 PB - Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG CY - Berlin AN - OPUS4-46143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terzioglu, T. A1 - Karthik, M. A1 - Hurlebaus, S. A1 - Hueste, M. A1 - Maack, Stefan A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert A1 - Krause, M. A1 - Miller, P. A1 - Olson, L. T1 - Nondestructive evaluation of grout defects in internal tendons of posttensioned girders JF - NDT and E International N2 - Post-tensioning systems provide safe and efficient construction solutions for long span bridges. Despite the improved grouting practices over the past decade, existing post-tensioning systems may have significant amount of grout defects, which could lead to corrosion of the strands. Condition assessment of post-tensioning systems is necessary to allow bridge owners to take timely, proactive actions to mitigate or prevent further Deterioration and unanticipated tendon failures. A detailed experimental study conducted to assess the performance of nondestructive evaluation techniques in detecting grout defects within internal tendons is presented herein. Nondestructive evaluation techniques that include Ground Penetrating Radar, Impact Echo, Ultrasonic Tomography, and Ultrasonic Echo are evaluated in terms of detecting the location and severity of fabricated grout defects in a full-scale post-tensioned U-girder mock-up specimen. While Ground Penetrating Radar can identify the location and profile of the internal tendons, particularly metal ducts due to strong reflections, this method did not provide any information about the defect conditions within the tendon. Both Impact Echo and Ultrasonic Echo techniques are effective in identifying the Location of grout defects, but could not differentiate between water, void, or compromised grout conditions. The study clearly demonstrates the need for NDE techniques that are applicable to anchorage regions, and that are capable of estimating the severity and nature of grout defects in internal tendons. KW - Zerstörungsfreie Prüfung KW - Nondestructive testing KW - Ground penetrating radar KW - Impact Echo KW - Ultrasonic tomography KW - Ultrasonic echo KW - Bridge inspection PY - 2018 UR - https://www.sciencedirect.com/science/article/pii/S0963869517305996?via%3Dihub DO - https://doi.org/10.1016/j.ndteint.2018.05.013 SN - 0963-8695 VL - 99 SP - 23 EP - 35 PB - Elsevier Ltd. AN - OPUS4-45218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -