TY - GEN A1 - Maack, Stefan A1 - Bertovic, Marija A1 - Radtke, Martin A1 - et al., ED - Wahlster, Wolfgang ED - Winterhalter, Christoph T1 - Deutsche Normungsroadmap künstliche Intelligenz N2 - Rund ein Jahr haben DIN und DKE in einem gemeinsamen Projekt mit dem Bundesministerium für Wirtschaft und Energie und zusammen mit ca. 300 Fachleuten aus Wirtschaft, Wissenschaft, öffentlicher Hand und Zivilgesellschaft an der Normungsroadmap Künstliche Intelligenz gearbeitet. Eine hochrangige Steuerungsgruppe unter dem Vorsitz von Prof. Wolfgang Wahlster hat die Erarbeitung koordiniert und begleitet. Ziel der Roadmap ist die frühzeitige Entwicklung eines Handlungsrahmens für die Normung und Standardisierung, der die internationale Wettbewerbsfähigkeit der deutschen Wirtschaft unterstützt und europäische Wertmaßstäbe auf die internationale Ebene hebt.(...) KW - Künstliche Intelligenz KW - Normung KW - Roadmap PY - 2020 UR - https://www.din.de/resource/blob/772438/ecb20518d982843c3f8b0cd106f13881/normungsroadmap-ki-data.pdf VL - 2020 SP - 1 EP - 232 AN - OPUS4-51733 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weise, Frank A1 - Millar, Steven A1 - Wilsch, Gerd T1 - Analyse des Tausalzeintrags in Fahrbahndeckenbetone mit neuartiger Prüftechnik T1 - Analysis of De-icing Salt in Concrete Pavement with a new type of Test Technology N2 - In den letzten Jahren sind im deutschen Bundesautobahnnetz vermehrt AKR-Schäden an Betonfahrbahndecken aufgetreten. Ursächlich hierfür ist die Verwendung alkaliempfindlicher Gesteinskörnung. Dies führt bei gleichzeitiger Anwesenheit von Wasser infolge der Exposition der Fahrbahndecke und des alkalischen Milieus durch den Einsatz alkalireicher Portlandzemente bei der Betonherstellung zu einer Alkali-Kieselsäure-Reaktion (AKR). Zusätzlich wird der AKR-Schädigungsprozess in Betonfahrbahndecken durch den externen Tausalzeintrag (primär NaCl) im Winter begünstigt. Vor diesem Hintergrund kommt der Ermittlung des Tausalzeintrags in den Fahrbahndeckenbeton eine große Bedeutung zu. Die Analyse des Tausalzeintrags erfolgte bisher ausschließlich nasschemisch an gemahlenen Bohrkernsegmenten. Nachteilig sind hierbei der relativ hohe prüftechnische Aufwand und die eingeschränkte Ortsauflösung. Der alternative Einsatz von LIBS (Laser-induced breakdown spectroscopy) eröffnet in diesem Kontext neue Möglichkeiten. So wird in diesem Beitrag anhand von Bohrkernen aus einem repräsentativen AKR-geschädigten BAB-Abschnitt exemplarisch die Vorgehensweise bei der LIBS-Analyse zur Ermittlung der Na- und Cl-Verteilung an vertikalen Schnittflächen von Bohrkernen aufgezeigt. Da der Tausalzeintrag primär über den Zementstein erfolgt, wurde der verfälschende Na-Grundgehalt der Gesteinskörnung mittels eines Ausschlusskriteriums (Ca-Gehalt) eliminiert. Vergleichend durchgeführte Cl-Mappings mit Mikroröntgenfluoreszenzanalyse sowie nasschemische Analysen belegen die Güte der durchgeführten LIBS-Messungen. Allerdings bedarf es bei der quantitativen Ermittlung des Natriumgehaltes in der Betonfahrbahndecke noch weitergehender Untersuchungen. N2 - Analysis of the intrusion of de-icing salt into concrete pavements by a novel test method In recent years the German motorway network has seen an increase in the occurrence of damage in concrete pavements. This has been caused by the use of alkali-sensitive aggregates. Given the exposure of the concrete pavement to water and the alkaline environment caused by the use of Portland cement during concrete mixing, this environment can lead to an alkali-silica reaction (ASR) process. This ASR-damage process in concrete pavements is further exacerbated by the external application of de-icing salt in winter. Against this background, the evaluation of the intrusion of de-icing salt becomes of great importance. Until now, the analysis of the intrusion of de-icing salt was carried out in a wet-chemistry process on finely ground segments of drilling cores. The disadvantages of this method are the relatively arduous testing process and the limited depth resolution. The alternative application of LIBS (laser-induced breakdown spectroscopy) offers new possibilities in this context. In this paper, the procedure for the LIBS analysis of sodium and chloride distribution on vertical cut surfaces of drilling cores taken from representative ASR-damaged concrete pavements is presented. Because the intrusion of de-icing salt takes place primarily in the cement matrix, the distorting effect of the sodium content in the aggregates was eliminated by an exclusion criteria (namely, the calcium content). The comparable chloride mappings by micro X-ray fluorescence spectroscopy and wet-chemical analysis confirm the quality of the LIBS measurements. However, additional investigations are necessary for the quantitative analysis of sodium content in concrete pavements. KW - Betonfahrbahndecke KW - Alkali-Kieselsäure-Reaktion KW - Tausalz KW - LIBS KW - MRFA KW - Nasschemie KW - ZfP PY - 2018 U6 - https://doi.org/10.1002/best.201800033 SN - 0005-9900 SN - 1437-1006 VL - 113 IS - 9 SP - 656 EP - 666 PB - Wilhelm Ernst & Sohn, Verlag für Architektur und technische Wissenschaften GmbH & Co. KG CY - Berlin AN - OPUS4-46171 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weise, Frank A1 - Kind, Thomas A1 - Stelzner, Ludwig A1 - Wieland, M. T1 - Dunkelfärbung der Betonfahrbahndecke im AKR-Kontext - Ursachenanalyse mit innovativer Prüftechnik T1 - Dark Dyeing of the Concrete Pavement in the AKR Context: Root Cause Analysis with innovative Testing Technology N2 - Die AKR-Schadensevolution von Betonfahrbahndecken ist in der Anfangsphase durch eine Dunkelfärbung der Oberfläche im Fugenbereich gekennzeichnet. Es wird vermutet, dass eine erhöhte Durchfeuchtung der Betonrandzone ursächlich für diese Erscheinung ist. Vor diesem Hintergrund wurde exemplarisch eine Fahrbahnplatte eines repräsentativen Bundesautobahnabschnitts systematisch mit verschiedenartiger zerstörungsfreier Prüftechnik vor Ort untersucht. Die Ergebnisse der zunächst erfolgten großflächigen Durchmusterung mit Radar zeigen, dass in den Bereichen mit einer Dunkelfärbung der Betonfahrbahndecke erhöhte Laufzeiten der Radarimpulse zwischen der Oberfläche und der Rückseite der Betonfahrbahndecke auftreten, was auf eine erhöhte integrale Durchfeuchtung der Betonfahrbahndecke schließen lässt. Vertiefend durchgeführte NMR-Feuchtemessungen in der Betonrandzone zeigen eine gute Korrelation zwischen erhöhtem Feuchtegehalt und der dunkel gefärbten Fahrbahnoberfläche. Die Ergebnisse beider zerstörungsfreien Prüfmethoden lassen den Schluss zu, dass die Betonfahrbahndecke in der Nähe des Fugenkreuzes eine höhere Durchfeuchtung als im Bereich der Querscheinfuge aufweist. Die geringste Durchfeuchtung besitzt die Betonfahrbahndecke in der Plattenmitte. Die mit den zerstörungsfreien Prüfverfahren ermittelten Befunde stimmen prinzipiell gut mit den punktuell mittels Darr-Wäge-Verfahren an Bohrmehlproben gewonnenen Ergebnissen überein. N2 - Darkening of the surface within alkali-silica reaction context - Root cause analysis with non-destructive measurement methods The damage evolution in concrete pavements due to alkali-silica reaction is characterized in the initial phase by a darkening of the surface along joint regions. It is generally assumed that an increased moisture content of the concrete boundary zone is responsible for this visual appearance. Against this background, a concrete pavement slab of a representative German motorway section was systematically investigated in-situ using different non-destructive measurement methods. The results of the high-resolution, planar radar showed an increased time of flight of the radar pulse between the pavement surface and the base of the concrete slab in the darkened areas. This indicated that the overall moisture content is increased near joints in the slab. Additional NMR moisture measurements in the concrete boundary zone confirmed the correlation between increased moisture content and the dark-colored surface of the concrete pavement. The results of both non-destructive measurement methods indicated that the moisture content near the intersection of two joints was higher than the moisture content near the area around the transverse joint. The lowest moisture content was measured in the center of the concrete pavement slab. The results obtained with the two non-destructive testing methods were in overall good agreement with moisture measurements of boring dust analyzed using the gravimetric method. KW - Betonfahrbahndecke KW - Alkali-Kieselsäure-Reaktion KW - Feuchtemessung KW - Radar KW - Nuclear Magnetic Resonance KW - ZfP PY - 2018 U6 - https://doi.org/10.1002/best.201800020 SN - 0005-9900 SN - 1437-1006 VL - 113 IS - 9 SP - 647 EP - 655 PB - Wilhelm Ernst & Sohn, Verlag für Architektur und technische Wissenschaften GmbH & Co. KG CY - Berlin AN - OPUS4-46173 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Grotelüschen, Bjarne A1 - Bartholmai, Matthias A1 - Strangfeld, Christoph ED - Kossa, A. ED - Kiss, R. T1 - Towards Autonomous NDT Inspection: Setup and Validation of an Indoor Localization System N2 - Monitoring and maintenance of civil infrastructure are of great importance, as any undetected damage can cause high repair costs, unintended deadtime, or endanger structural integrity. The inspection of large concrete structures such as bridges and parking lots is particularly challenging and time-consuming. Traditional methods are mostly manual and involve mapping a grid of measurement lines to record the position of each measurement. Current semi-automated methods, on the other hand, use GPS or tachymeters for localization but still require trained personnel to operate. An entirely automated approach using mobile robots would be more cost- and time-efficient. While there have been developments in using GPS-enabled mobile robots for bridge inspection, the weak signal strength in indoor areas poses a challenge for the automated inspection of structures such as parking lots. This paper aims to develop a solution for the automated inspection of large indoor concrete structures by addressing the problem of robot localization in indoor spaces and the automated measurement of concrete cover and rebar detection. T2 - 39th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Siófok, Hungary DA - 26.09.2023 KW - NDT Inspection KW - Mobile Robot KW - Indoor Localization KW - Setup and Validation PY - 2023 SN - 978-963-421-927-9 SP - 88 EP - 89 PB - Hungarian Scientific Society of Mechanical Engineering (GTE) CY - Siófok, Hungary AN - OPUS4-58660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epple, Niklas A1 - Fontoura Barroso, Daniel A1 - Niederleithinger, Ernst T1 - Monitoring of Concrete with Embedded Ultrasound Sensors, Coda Waves and a Novel Measurement Device N2 - Using embedded ultrasound (US) sensors in civil engineering structures and Coda Wave Interferometry (CWI), DFG research group CoDA aims for developing methods of concrete damage assessment by combination of Micro and macro scale simulations and experiments. BAMs goal within the project is the provision of small and durable measurement equipment on the one hand, and the investigation of damage sensitive parameters and development of an imaging algorithm on the other hand. In this study we focus on the development of the measurement system and the influence of temperature variations on the measurements. T2 - Summer School DFG FOR CoDA CY - Berchtesgaden, Germany DA - 27.09.2020 KW - Ultrasound KW - Coda Wave Interferometry KW - Structural Health Monitoring PY - 2020 AN - OPUS4-51382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maack, Stefan A1 - Benner, Philipp A1 - Kröll, Mirco A1 - Prager, Jens A1 - Daum, Werner A1 - Casperson, Ralf A1 - Heckel, Thomas A1 - Spaltmann, Dirk A1 - et al., ED - Wahlster, W. ED - Winterhalter, C. T1 - Deutsche Normungsroadmap künstliche Intelligenz Ausgabe 2 N2 - Im Auftrag des Bundesministeriums für Wirtschaft und Klimaschutz haben DIN und DKE im Januar 2022 die Arbeiten an der zweiten Ausgabe der Deutschen Normungsroadmap Künstliche Intelligenz gestartet. In einem breiten Beteiligungsprozess und unter Mitwirkung von mehr als 570 Fachleuten aus Wirtschaft, Wissenschaft, öffentlicher Hand und Zivilgesellschaft wurde damit der strategische Fahrplan für die KI-Normung weiterentwickelt. Koordiniert und begleitet wurden diese Arbeiten von einer hochrangigen Koordinierungsgruppe für KI-Normung und -Konformität. Mit der Normungsroadmap wird eine Maßnahme der KI-Strategie der Bundesregierung umgesetzt und damit ein wesentlicher Beitrag zur „KI – Made in Germany“ geleistet. Die Normung ist Teil der KI-Strategie und ein strategisches Instrument zur Stärkung der Innovations- und Wettbewerbsfähigkeit der deutschen und europäischen Wirtschaft. Nicht zuletzt deshalb spielt sie im geplanten europäischen Rechtsrahmen für KI, dem Artificial Intelligence Act, eine besondere Rolle. KW - Digitalisierung KW - Künstliche Intelligenz KW - Data Sciences KW - Normung Roadmap PY - 2022 SP - 1 EP - 448 AN - OPUS4-56576 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prabhakara, Prathik A1 - Mielentz, Frank A1 - Stolpe, Heiko A1 - Behrens, Matthias A1 - Lay, Vera A1 - Niederleithinger, Ernst T1 - Construction and validation of a novel phased array borehole probe for ultrasonic investigations at sealing structures in radioactive repositories N2 - A new type of ultrasonic borehole probe is currently under development for the quality assurance of sealing structures in radioactive waste repositories using existing research boreholes. The goal is to examine the sealing structures made of salt concrete for possible cracks, delamination, and embedded objects. Earlier prototype probes use 12 or 16 individual dry point contact (DPC) horizontal shear wave transducers grouped into a transmitter and a receiver array, each made up of six or eight individual transducers. They are operated with a commercially available portable ultrasonic flaw detector used in the civil engineering industry. To increase the generated sound pressure of the borehole probe, the number of transducers in the novel probe is increased to 32. In addition, timed excitation of each probe is used to direct a focused sound beam to a specific angle and distance based on calculated time delays. Hence, the sensitive test volume is limited, and the signal-to-noise ratio of the received signals is improved. This paper presents the validation of the newly developed phased array borehole probe by beam computation in CIVA software and experimental investigations on a semi-cylindrical test specimen to investigate the directional characteristics. In combination with geophysical reconstruction techniques, an optimised radiation pattern of the probe is expected to improve the signal quality and thus increase the reliability of the imaging results. This is of great importance for the construction of safe sealing structures needed for the disposal of radioactive or toxic waste. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Borehole probe KW - Phased array technique KW - SealWasteSafe KW - Monitoring KW - Engineered barrier; PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-568016 SN - 1435-4934 SP - 1 EP - 4 PB - NDT.net AN - OPUS4-56801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Clauß, F. A1 - Epple, Niklas A1 - Ahrens, M. A. A1 - Niederleithinger, Ernst A1 - Mark, P. T1 - Comparison of Experimentally Determined Two-Dimensional Strain Fields and Mapped Ultrasonic Data Processed by Coda Wave Interferometry N2 - Due to the high sensitivity of coda waves to the smallest structural alterations such as strain, humidity or temperature changes, ultrasonic waves are a valid means to examine entire structures employing networks of ultrasonic transducers. In order to substantiate this ex ante assessment, the viability of measuring ultrasonic waves as a valid point of reference and inference for structural changes is to be further scrutinized in this work. In order to investigate the influence of mechanical strain on ultrasonic signals, a four-point bending test was carried out on a reinforced concrete beam at Ruhr University Bochum. Thus, measurements collected from a network of selected transducer pairings arranged across the central, shear-free segment of the test specimen, were correlated to their respective strain fields. Detected ultrasonic signals were evaluated employing Coda Wave Interferometry. Such analysis comprised the initial non-cracked state as well as later stages with incremental crack depth and quantity. It was to ascertain that the test specimen can in fact be qualitatively compartmentalized into areas of compression and tension identified via Relative Velocity Changes presented in Attribute Maps. However, since results did not entail a zero crossing, i.e., neither positive nor negative values were to be calculated, only relative changes in this work displayed staggered over the height of the object under test, are discussed. Under the given methodological premises, additional information is currently required to make quantitative assertions regarding this correlation of ultrasonic and strain results. This holds true for the comparability of the ultrasonic and strain results for both non-cracked and even the cracked state. KW - Digital image correlation KW - Fiber optic sensors KW - Coda Wave Interferometry KW - Ultrasound KW - Concrete PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-510501 SN - 1424-8220 VL - 20 IS - 14 SP - Paper 4023, 1 PB - MDPI CY - Basel AN - OPUS4-51050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Diewald, F. A1 - Epple, Niklas A1 - Kraenkel, T. A1 - Gehlen, C. A1 - Niederleithinger, Ernst T1 - Impact of External Mechanical Loads on Coda Waves in Concrete N2 - During their life span, concrete structures interact with many kinds of external mechanical loads. Most of these loads are considered in advance and result in reversible deformations. Nevertheless, some of the loads cause irreversible, sometimes unnoticed changes below the macroscopic scale depending on the type and dimension of the impact. As the functionality of concrete structures is often relevant to safety and society, their condition must be known and, therefore, assessed on a regular basis. Out of the spectrum of non-destructive monitoring methods, Coda Wave Interferometry using embedded ultrasonic sensors is one particularly sensitive technique to evaluate changes to heterogeneous media. However, there are various influences on Coda waves in concrete, and the interpretation of their superimposed effect is ambiguous. In this study, we quantify the relations of uniaxial compression and uniaxial tension on Coda waves propagating in normal concrete. We found that both the signal correlation of ultrasonic signals as well as their velocity variation directly reflect the stress change in concrete structures in a laboratory environment. For the linear elastic range up to 30% of the strength, we calculated a velocity variation of −0.97‰/MPa for compression and 0.33%/MPa for tension using linear regression. In addition, these parameters revealed even weak irreversible changes after removal of the load. Furthermore, we show the time-dependent effects of shrinkage and creep on Coda waves by providing the development of the signal parameters over time during half a year together with creep recovery. Our observations showed that time-dependent material changes must be taken into account for any comparison of ultrasonic signals that are far apart in time. The study’s results demonstrate how Coda Wave Interferometry is capable of monitoring stress changes and detecting even small-size microstructural changes. By indicating the stated relations and their separation from further impacts, e.g., temperature and moisture, we anticipate our study to contribute to the qualification of Coda Wave Interferometry for its application as an early-warning system for concrete structures. KW - Ultrasound KW - Coda Wave Interferometry (CWI) KW - Mechanical Load KW - Microstructure KW - Concrete PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-556878 SN - 1996-1944 VL - 15 IS - 16 SP - 1 EP - 15 PB - MDPI AN - OPUS4-55687 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 - Non-Destructive Testing: A valuable source of information for reliability assessments N2 - The reassessment of bridges is becoming increasingly important. The basic requirement for analyses of structural safety is reliable knowledge about individual structures. This paper introduces the new approach to evaluate the quality of measured data gained from non-destructive testing (NDT) to provide reliable, objective, and relevant information about existing bridges. The purpose is to relate this validated knowledge to probabilistic analyses. Bridging the gap between NDT and numerical reassessments indicates reduced numerical uncertainties and residual service time extensions. This paper deals with an application of this approach using measurement data collected by ultrasonic technique at a prestressed concrete bridge. T2 - IABSE Symposium 2019 CY - Guimarães, Portugal DA - 27.03.2019 KW - NDT KW - Measurement KW - Structural safety KW - Concrete bridges KW - Eexisting structures PY - 2019 AN - OPUS4-47714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -