TY - CONF A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Niederleithinger, Ernst T1 - Practical procedure for the precise measurement of geometrical tendon positions in concrete with ultrasonic echo N2 - Existing concrete structures were usually designed for lifetimes of several decades. The current and urgently required efforts to increase sustainability and protect the environment will likely result in extended service lives up to 100 years. To achieve such objectives, it is required to assess structures over their entire lifecycles. Non-destructive testing (NDT) methods can reliably support the assessment of existing structures during the construction, operational, and decommissioning phases. One of the most important and safety-relevant components of a prestressed concrete structure are the tendons. NDT methods such as the ultrasonic echo method are suitable for both the detection and the localization of the tendons, i.e., the measurement of their geometrical position inside the component. The uniqueness of structures, concrete heterogeneity, and varying amounts of secondary components such as the reinforcement represent obstacles in the application of these methods in practice. The aim of this contribution is to demonstrate a practicable procedure, that can be used in the field to determine the parameters required for the measuring data analysis without extensive knowledge about the investigated components. For this purpose, a polyamide reference specimen is used to show which steps are required to obtain reliable imaging information on the position of tendons from the measurement data. The procedure is then demonstrated on a concrete test specimen that covers various relevant and practice-oriented test scenarios, such as varying tendon depths and component thicknesses. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2022) CY - Cape Town, South Africa DA - 03.10.2022 KW - Validation KW - Non-destructive testing KW - Ultrasonic KW - Reconstruction KW - Concrete KW - Tendon duct PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559979 DO - https://doi.org/10.1051/matecconf/202236403007 SN - 2261-263X SP - 1 EP - 8 AN - OPUS4-55997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Bartolac, M. A1 - Bien, J. A1 - Górski, M. A1 - Keßler, S. A1 - Küttenbaum, Stefan A1 - Kuzawa, M. A1 - Ley, J. A1 - Maack, Stefan A1 - Mendler, A. A1 - Ryjáček, P. A1 - Santos, L. A1 - Verstrynge, E. ED - Keßler, S. ED - Limongelli, M. P. ED - Apostolidi, E. T1 - Chapter 2: Condition survey - Testing and monitoring methods N2 - The through-life management of our constantly ageing infrastructure is a basic requirement in order to ensure their structural safety and serviceability. Each structure experiences deterioration processes with time leading to a decrease of structural safety and serviceability. The design of new structures considers the expected deterioration for a defined period, the design service life. However, a frequent survey of structural safety controlling structural condition should be mandatory and a maintenance plan should be an integral part of the design. In addition, many structures have exceeded their design service life already or are very close to it leading to an increasing demand for condition assessment. On the one hand, assumptions made during design are not valid any more due to change of the loads, e.g., increasing traffic loads in terms of number and weights. On the other hand, design codes evolved over time in such a way that existing structures do not comply with today’s standards. In all these cases, the through-life management is an important tool to maintain the accessibility of existing structures with known reliability. In line with the new Model Code for Concrete Structures, which includes guidance for both – design of new structures and assessment of existing structures, the Task Group 3.3 focused on the compilation of a state-of-the-art guideline for the through-life management of existing concrete structures, including: Data acquisition by testing and monitoring techniques; Condition assessment for the evaluation of existing structures; Performance prediction using advanced methods; Decision-making procedures to perform a complete assessment of existing structure. The overall objective of the through-life management is the assessment of the current condition and the estimation of the remaining service life under consideration of all boundary conditions. KW - Life management KW - Concrete KW - Non-destructive testing KW - Structural health monitoring KW - State-of-the-art PY - 2023 UR - https://doi.org/10.35789/fib.BULL.0109 SN - 978-2-88394-172-4 DO - https://doi.org/10.35789/fib.BULL.0109.Ch02 SN - 1562-3610 VL - fib Bulletin 109 SP - 16 EP - 38 PB - Fédération internationale du béton (fib) CY - Lausanne AN - OPUS4-59110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Küttenbaum, Stefan A1 - Braml, T. A1 - Taffe, A. A1 - Maack, Stefan ED - Pellegrino, C. ED - Faleschini, F. ED - Zanini, M.A. ED - Matos, J.C. ED - Casas, J.R. ED - Strauss, A. T1 - From Uncertainty in Measurement to Certainty in Bridge Reassessment N2 - "The reassessment of bridges continues to take great importance both nationally and internationally. A major challenge is to find computation models reflecting the actual properties of the considered structures sufficiently accurate. Besides regular inspections, the conduction of advanced measurements is suitable to generate reliable information about a structure to be assessed. Prior to incorporating measurement results in reassessment, the relevance, the trueness, and the precision of the measured information needs to be stated. On the one hand, the use of information whose quality has not been assessed can lead to errors with serious consequences. On the other, the measurement of irrelevant information is inefficient. Although the use of measured data in assessment is currently mostly unregulated, their appreciation in reliability analyses is beneficial since the built environment can be assessed more realistically. Utilizing NDT in reassessment has the potential to extend remaining lifetimes of a structure, save resources, and improve infrastructural availabilities. The power of judgment regarding the decision on the reliability of an existing structure can be increased. In this contribution, an approach is outlined to process non-destructively gathered measurement data in a comparableway in order to include themeasured information in probabilistic reliability assessments of existing structures. An essential part is the calculation of measurement uncertainties. The effect of incorporating evaluated NDT-results is demonstrated by means of a prestressed concrete bridge and GPR measurements conducted on this bridge as a case-study. The bridge is assessed regarding SLS Decompression using the NDT-results." KW - Reliability KW - Assessment KW - Existing structures KW - NDT KW - Concrete PY - 2022 DO - https://doi.org/10.1007/978-3-030-91877-4_58 VL - 200 SP - 509 EP - 517 PB - Springer CY - Cham AN - OPUS4-54019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Jansen, D. A1 - Bald, S. A1 - Birbaum, J. A1 - Küttenbaum, Stefan A1 - Krause, J. A1 - Maack, Stefan A1 - Pichottka, S. A1 - Scherkenbach, M. A1 - Strangfeld, Christoph A1 - Villaret, K. A1 - Wöllenstein, J. T1 - Sensors for the structural assessment of roads N2 - This working paper summarises the current state of knowledge and research on the application of sensors in road pavements, designed to record input quantities and characteristics for structural assessment. In this working paper, sensors generally refer to technical equipment that can used to record the values of physical quantities and display them for interpretation. The working paper deals with every type of sensor that is permanently connected to the road, i.e. sensors that are installed – in the bound and unbound courses of the superstructure as well as in the sub-base/sub-structure, – next to or above the road (for example on masts) and can contribute to structural recording and its subsequent assessment. This can also include sensors that are primarily used for a different purpose (e.g. traffic control). However, this working paper only describes the application of sensors that are installed primarily for other purposes for the sake of completeness; special publications (e.g. Notes on detection technologies in road traffic) are available for the respective installation situations. KW - Asphalt KW - Concrete KW - Measurement chain KW - Sensor technology KW - Condition assessment PY - 2024 SP - 1 EP - 36 PB - Forschungsgemeinschaft für Straßen- und Verkehrswesen e.V. CY - Köln AN - OPUS4-60084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan A1 - Taffe, A. T1 - Imaging of results in NDT-CE: Strength and limitations in the use of Radar vs. Ultrasonic Echo N2 - Presentation on behalf of the co-author specified in BAM-Publica. Study on capabilities of volume methods (GPR, Ultrasonic Echo) regarding lateral and depth localisation of reinforcement and tendons in concrete components. Varied boundary conditions: spacing and diameter of both the near surface rebars of the mesh, and the reflectors of interest, as well as component thickness and concrete cover. Please find corresponding references on slide 2. T2 - 6th International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR2022) CY - Cape Town, South Africa DA - 03.10.2022 KW - Reinforcement KW - Tendon duct KW - Concrete KW - NDT KW - Localisation PY - 2022 AN - OPUS4-55987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan A1 - Taffe, A. A1 - Braml, T. A1 - Maack, Stefan T1 - Reliability assessment of existing bridges based on NDT-results 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 - 5th ICCRRR 2018 - International Conference on Concrete Repair, Rehabilitation and Retrofitting CY - Cape Town, South Africa DA - 19.11.2018 KW - NDT KW - Concrete KW - Stochastic model KW - Reassessment KW - Reliability PY - 2018 AN - OPUS4-46768 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan A1 - Braml, T. A1 - Taffe, A. A1 - Maack, Stefan T1 - From uncertainty in measurement to certainty in bridge assessment N2 - In this contribution, an approach is outlined to process non-destructively gath-ered measurement data in a comparable way in order to include the measured information in probabilistic reliability assessments of existing structures. An es-sential part is the calculation of measurement uncertainties. The effect of incor-porating evaluated NDT-results is demonstrated by means of a prestressed con-crete bridge and GPR measurements conducted on this bridge as a case-study. The bridge is assessed regarding SLS Decompression using the NDT-results. T2 - 1st Conference of the European Association on Quality Control of Bridges and Structures – EUROSTRUCT2021 CY - Padova, Italy DA - 29.08.2021 KW - Reliability KW - Assessment KW - Existing structures KW - NDT KW - Concrete PY - 2021 AN - OPUS4-53173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -