TY - JOUR A1 - Kowitz, Astrid A1 - Wu, Cheng-Chieh A1 - Helmerich, Rosemarie A1 - Hille, Falk A1 - Kadoke, Daniel A1 - Gründer, Klaus-Peter A1 - Hauser, S. A1 - Schwarzinger, H. ED - Bland, S. T1 - Impact on a micro-reinforced UHPC: Experimental studies versus numerical modeling JF - Materials Today: Proceedings N2 - Within the presented research project, experimental and numerical investigations were performed to develop a thin-shelled, modular, mobile element system made of a micro-reinforced ultra-high-performance ductile concrete (DUCON®). Material parameters were experimentally determined to adapt the material model within the numerical analysis applying the Drucker-Prager relationship. Afterwards, for validation of the numerical models, quasi-static and high-velocity impact tests were performed on plate-like structures. Finally, a suitable geometry of transportable barrier elements will be designed, which provides a maximum of resistance against impact by a minimum of weight and a maximum of mobility. KW - UHPC KW - Impact KW - DUCON® KW - Quasi-static and dynamic tests KW - Micro-reinforcement KW - Ductility KW - Mobile elements KW - Numerical modeling KW - Stereo photogrammetry KW - Compressive strength KW - E-modulus PY - 2019 UR - https://www.sciencedirect.com/science/article/pii/S2214785319305115?dgcid=author DO - https://doi.org/10.1016/j.matpr.2019.03.152 SN - 2214-7853 VL - 12 IS - 2 SP - 474 EP - 483 PB - Elsevier Ltd CY - Amsterdam AN - OPUS4-48181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moldenhauer, Laura A1 - Helmerich, Rosemarie A1 - Köppe, E. A1 - Wittmann, H.-J. T1 - Experimental modeling approach for determining the moisture damping exponent of a bluetooth low energy signal in moist building material JF - MaterialsToday: Proceedings N2 - The presented development of a damping model is a research component of an experimental feasibility study about moisture in building materials measured with Bluetooth® Low Energy (BLE) signals. This study may be part of a structural health- and long-term monitoring aiming at early damage detection in the built infrastructure and is increasingly focusing on wireless sensor network technology. It is investigated, how the Received Signal Strength Indicator (RSSI) of a BLE signal, transmitted from the BLE-module embedded in building materials with changing moisture content is damped. The aim of the modelling is the derivation of a damping equation for the formal model to determine the moisture damping exponent to finding a correlation. T2 - 34th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Trieste, Italy DA - 19.09.2017 KW - BLE Bluetooth low energy KW - Sensor network KW - RSSI Received Signal Strength Indicator KW - Structural Health Monitoring KW - Moisture measurements PY - 2018 DO - https://doi.org/10.1016/j.matpr.2018.08.124 SN - 2214-7853 VL - 5 IS - Issue 13, Part 2 SP - 26469 EP - 26792 PB - Elsevier Ltd. CY - Radarweg 29, 1043 NX Amsterdam, The Netherlands AN - OPUS4-47171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hong, Shuxian A1 - Wiggenhauser, Herbert A1 - Helmerich, Rosemarie A1 - Peng, B.D. A1 - Xing, D. F. T1 - Long-term monitoring of reinforcement corrosion in concrete using ground penetrating radar JF - Corrosion Science N2 - A new method for periodically monitoring reinforcement corrosion in concrete with Ground-Penetrating Radar (GPR) is proposed and a ten-year long-term corrosion periodic monitoring experiment is reported. GPR historical data was taken in different years, under different conditions. In order to align and normalize the obtained images properly prior to effectively performing any automatic defect detection, image registration techniques based on mutual-information are employed, and a new signal processing scheme is proposed for normalizing the intensity of GPR images. Then, the processed image results can be used to compare and find out the change of GPR detection due to corrosion. KW - Steel reinforced concrete KW - Atmospheric corrosion KW - Pitting corrosion PY - 2017 DO - https://doi.org/10.1016/j.corsci.2016.11.003 SN - 0010-938X VL - 114 SP - 123 EP - 132 PB - Elsevier Ltd. AN - OPUS4-38346 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moldenhauer, Laura A1 - Helmerich, Rosemarie A1 - Köppe, Enrico A1 - Haamkens, Frank A1 - Wittmann, Jochen ED - Emri, Igor T1 - Experimental feasibility study about moisture in building materials measured with Bluetooth JF - Materials Today: Proceedings N2 - Structural health monitoring contributes to early damage detection in the built infrastructure. During the last two decades, sensor networks transferred from wired to wireless sensor networks. Several methods exist to measure moisture in building materials. Most of the introduced commercial moisture measurement methods provide information about the local or near surface moisture. A feasibility study is presented to demonstrate, how the Received Signal Strength Indicator (RSSI) of a Bluetooth Low Energy (BLE) signal, transmitted from the BLE-module embedded in building materials, correlate with changing moisture content. The feasibility of this influence was investigated in the presented study. The maximum and minimum RSSI were systematically recorded and analysed. T2 - 33nd Danubia Adria Symposium on Advances in Experimental Mechanics CY - Portoroz, Slovenia DA - 20.09.2016 KW - BLE KW - Long-Term Monitoring KW - Network KW - Structural Health Monitoring KW - Moisture Measurement KW - RSSI KW - Bluetooth Low Energy KW - Sensor PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S2214785317308398 DO - https://doi.org/10.1016/j.matpr.2017.06.053 SN - 2214-7853 VL - 4 IS - 5, Part 1 SP - 5889 EP - 5892 PB - Elsevier Ltd. AN - OPUS4-41585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppe, Enrico A1 - Moldenhauer, Laura A1 - Haamkens, Frank A1 - Helmerich, Rosemarie T1 - Feuchtemessung in Bauteilen und anderen Strukturen mit Bluetooth Low Energy JF - Bautechnik N2 - Die Langzeitüberwachung von Bauteilen (Structural Health Monitoring, SHM) ging in den letzten Jahren zunehmend von verkabelten Sensoren zu kabellosen Sensornetzwerken (WSN) über. Frühwarnsysteme sollen rechtzeitige Signale senden, wenn Schädigungsprozesse einsetzen, wenn ein Bauteil z. B. zu feucht wird (Deiche, Staumauern), oder wenn Feuchteprozesse in Bauteilen auftreten, die den Transport von schädlichen Stoffen ermöglichen. Mittels handelsüblicher multifunktionaler Sensoren wie einem Bluetooth Low Energy (BLE) wurden erste Machbarkeitsuntersuchungen zur Massenfeuchtemessung durchgeführt. Die untersuchten Parameter sind der sogenannte Received Signal Strength Indicator (RSSI) eines Bluetooth-Low-Energy(BLE)-Signals und die abgestrahlte Sendeleistung eines eingebetteten BLE-Moduls. Das BLE-Modul kommuniziert mit einem mobilen smarten Empfänger wie einem Tablet oder einem Smartphone als SmartHub. Die Veränderung des RSS-Indikators ist ein Maß für die Veränderung der Feuchte im Bauteil, während die ausgesandte Signalstärke konstant bleibt. Wenn das BLE-Signal einen feuchten Bereich im Baumaterial durchläuft, verändert sich der RSS-Indikator. Nach erfolgreicher Machbarkeitsstudie wurde nun ein aus dem Netzwerk MI4G (Modern Industry for Germany) zwischen der Bundesanstalt für Materialprüfung und dem Klein- und mittelständigen Unternehmen LinTech GmbH heraus beantragtes ZIM-Projekt bewilligt. Der Bericht zeigt erste Ergebnisse von Voruntersuchungen und gibt einen Ausblick auf weitere Forschungsaktivitäten. KW - Bluetooth KW - BLE KW - Feuchtemessung KW - Bauteil KW - Bluetooth Low Energy PY - 2016 UR - http://onlinelibrary.wiley.com/doi/10.1002/bate.201600074/epdf DO - https://doi.org/10.1002/bate.201600074 SN - 0932-8351 A 1556 VL - 93 IS - 10 SP - 747 EP - 751 PB - Ernst & Sohn CY - Deutschland AN - OPUS4-38163 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie T1 - Sanierung der Berliner U-Bahnlinie U1 JF - Restaurator im Handwerk N2 - Brücken zählen einerseits zu den ältesten Zeugnissen der Verkehrsgeschichte und sind andererseits ein wichtiger Bestandteil der Verkehrsinfrastruktur für unsere heutige Gesellschaft. Sie erfüllen eine wichtige Funktion bei Transport von Personen und Gütern und prägen das Stadtbild. Die Berliner Hoch- und Untergrundbahn, eröffnet im Februar 1902 nach 5 1/2 –jähriger Bauzeit, ist in der heutigen Berliner Denkmalliste als Denkmalbereich (Gesamtanlage) geschützt. Bereits seit 1980 waren die historischen Bahnhöfe entlang der Stammstrecke als Baudenkmale gelistet. An der Stahlkonstruktion der Hochbahnviadukte zwischen Halleschem Tor und Prinzenstraße wurden während regulärer Inspektionen in den 1990ziger Jahren Risse dokumentiert. Die Berliner Verkehrsbetriebe (BVG) bezogen die Bundesanstalt für Materialforschung und –prüfung (BAM) sowie Ingenieurbüros in eine Diskussion über die optimale Lösung zur Sanie-rung und zum Erhalt der Hochbahnviadukte ein. Zahlreiche Versuche im Labor und Messungen vor Ort dienten der Optimierung der bevorzugten Sanierungsvariante. Die BVG für eine Lösung mit relativ geringem Eingriff in die Konstruktion. Das äußere Erscheinungsbild der Hochbahnviadukte im Berliner Stadtbild konnte durch die Sanierungsvariante der BVG erhalten werden. KW - U-Bahn KW - Hochbahnviadukt KW - Denkmalschutz KW - Dehnungsmessungen KW - Sanierung KW - Elastisch gebettete Schiene KW - Schotterfreier Oberbau PY - 2016 SN - 1869-7119 IS - 3 SP - 39 EP - 45 PB - Bundesvereinigung Restaurator im Handwerk e.V. CY - Herrstein AN - OPUS4-38089 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hong, Shuxian A1 - Lai, W.-L. A1 - Helmerich, Rosemarie T1 - Experimental monitoring of chloride-induced reinforcement corrosion and chloride contamination in concrete with ground-penetrating radar JF - Structure and infrastructure engineering N2 - In this article, we present a laboratory experiment to monitor the accelerated corrosion in concrete using ground-penetrating radar (GPR). Four concrete test specimens were cast with rebars of different size and placed at different depths. The lifetime decades of reinforcement corrosion process were accelerated into 18 days by using the impress current technique. The electrochemical corrosion process was periodically monitored with GPR. Two control specimens were also prepared to investigate the influence of chloride contamination on GPR signal. The measured data were analysed both in time and frequency domains. In time domain, the peak-to-peak amplitude of a wave reflected by a rebar was calculated to investigate the relationship between an increase in signal amplitude and the degree of corrosion. In frequency domain, the time–frequency representations of the signal were computed by using S-transform. The results show that reinforce corrosion increased the amplitude of reflected signal in time domain but did not change the peak frequency in frequency domain while chloride contamination attenuates the signal to smaller amplitude and lower peak frequency. Based on the results, a novel process is finally proposed for GPR-based corrosion detection. KW - Non-destructive KW - Reinforcement corrosion KW - GPR KW - Chloride KW - Moisture KW - S-transform PY - 2015 DO - https://doi.org/10.1080/15732479.2013.879321 SN - 1573-2479 VL - 11 IS - 1 SP - 15 EP - 26 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-33085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Milmann, Boris A1 - Wöstmann, Jens T1 - Non-destructive detection of surface-bond defects in carbon composite-strengthened concrete structures JF - Structure and infrastructure engineering N2 - For almost 15 years, carbon fibre-reinforced polymer (CFRP) plates and sheets have been used for strengthening and repair of civil engineering structures. CFRP plates were applied to upgrade structures for change in use or increasing traffic load. CFRP laminates have also been used to repair deteriorated structures such as multi-storey parking or bridges. The execution quality and condition of the strengthening measure in terms of bond integrity were neither monitored nor tested systematically. Inspectors eventually applied simple hammer knocking during regular main inspection for subjective noise distinction as a measure for eventual insufficient bond. This paper presents the feasibility and the limitations of low-frequency transversal ultrasonic waves with dry-coupling point-contact sensors for inspection and defect detection between CFRP laminate and concrete surfaces. The German Centre of Competence in Civil Engineering (DIBt) has initiated a national research project [Helmerich et al. (2012). Condition analysis of bonded CFRP-applications on concrete structures by means of non-destructive testing [in German: Zustandsuntersuchung von CFK-Klebeverstärkungen an Betonbauteilen mittels zerstörungsfreier Prüfung (ZfP)]. Final, internal project report], carried out at the Federal Institute for Materials Research and Testing (BAM), Germany. The aim of the project was to present a potential non-destructive testing method for bond defect detection as a measure for the durability of the strengthening system more than 10 years after application. KW - Concrete bridges KW - Strengthening KW - Non-destructive testing KW - Composite materials KW - Durability KW - Inspection PY - 2015 DO - https://doi.org/10.1080/15732479.2013.879322 SN - 1573-2479 VL - 11 IS - 1 SP - 3 EP - 14 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-33086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Adam, Louisa A1 - Villalobos, S. A1 - Guimaraes, M. A1 - Wiggenhauser, Herbert T1 - Detection of cracks perpendicular to the surface using acoustic methods JF - The e-journal of nondestructive testing & ultrasonics N2 - Cracks perpendicular to the surface may be initial indicators for a deterioration process of concrete structures. Moisture penetrates inside the structure and transports adverse chemicals. The paper presents an investigation about the reliability of available commercial non-destructive evaluation techniques to reliably estimate the depth of surface-breaking cracks in reinforced concrete structures. Aim of the study was the investigation of surface-braking cracks under laboratory conditions. Commercial acoustic devices as impact echo equipment, single ultrasonic transducers and arrays were applied even if they have not been developed for this purpose. The commercial software and descriptions for application was followed strictly to compare the function, precision and repeatability of the measurements. Both, perpendicular notches and cracks have been considered. The study was completed with a discussion about reference specimens. The study was the basis for formulation of gaps in research. The Electric Power Research Institute (EPRI) has initiated and funded a Project. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Acoustic test KW - Commercial acoustic devices KW - Ultrasonic test KW - Crack depth KW - Concrete specimens PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345729 UR - https://www.ndt.net/?id=18412 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 9 PB - NDT.net CY - Kirchwald AN - OPUS4-34572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Zunkel, Astrid T1 - Partial collapse of the Berlin Congress Hall on May 21st, 1980 JF - Engineering failure analysis N2 - The Berlin Congress Hall was a gift of the United States of America to Germany for the Berlin World Exhibition in 1957. The elegantly double-curved roof was made from an advanced prestressed concrete construction. The construction followed the design by the American architect Hugh Stubbins with special structural modifications to comply with German construction rules. No early indications for failure initiation were detected before a sudden partial collapse. On May 21st, 1980, the Southern external roof overhang collapsed. In December 1980, Jörg Schlaich and his co-authors published a summarizing expert opinion about structural causes of failure. The present paper mainly introduces results of cause analysis made at the Federal Institute for Materials Research and Testing (BAM), mandated by the Public Prosecutor at the Berlin District Court to specify the causes of the sudden failure. This paper refers to BAM-publications about analyses that were performed under this mandate and published – most of them in German language – within the first years after failure. The expert's opinions comprise structural considerations materials investigations, metallographic analyses and corrosion. Nowadays experts have learnt from the failure and built a slightly modified roof in the original shape at the 750th birthday of the city of Berlin and re-opened the former Berlin Congress Hall to the public on May 9th, 1987. The Hall is now serving as the House of the Cultures of the World, following the initial intention of the hall. KW - Partial collapse KW - Berlin Congress Hall KW - Analysis KW - Stress corrosion cracking KW - Reconstruction PY - 2014 DO - https://doi.org/10.1016/j.engfailanal.2013.11.013 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 107 EP - 119 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-30863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Portella, Pedro Dolabella A1 - Helmerich, Rosemarie T1 - Adolf Martens and his contribution to materials engineering JF - Engineering failure analysis N2 - Adolf Martens (1850–1914) was a pioneer of materials engineering. After his studies in Berlin he joined a railway company being responsible for the technical equipment. His interest for the basic mechanisms of mechanical strength and fracture of metallic materials led him to the development of the basic concepts for metallography; his papers published between 1878 and 1889 laid the fundament of this technique. In 1880 Martens changed to the Royal Industrial Academy in Berlin and by 1884 he was designated as director of the Materials Testing Laboratory at the Technical University Berlin. Under his guidance this institution acquired an excellent reputation in all relevant areas of the German industry, forming the nucleus of the Bundesanstalt für Materialforschung und -prüfung (BAM) – the Federal Institute for Materials Research and Testing. Martens developed equipment in many different areas as mechanical testing of metallic materials and of paper, characterization of the wear behavior of materials and viscosity of lubricants. His overwhelming contribution to materials engineering was recognized as early as 1895 by Floris Osmond, who denominated martensite a metallographical constituent resulting from quenching of steels. In 2000 ISO designated the value obtained from the instrumented indentation method as Martens Hardness – HM. KW - Adolf Martens KW - Microscopy KW - Metallography KW - Mechanical testing KW - Quality assurance in materials testing PY - 2014 DO - https://doi.org/10.1016/j.engfailanal.2014.03.001 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 2 EP - 10 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-30865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Herter, Jürgen T1 - Root cause analysis of cracks in old steel viaducts and retrofitting JF - Engineering failure analysis N2 - Following the long tradition of the Federal Institute for Materials Research and Testing (BAM) since Adolf Martens has created first routines in failure analysis (Ruske, 1971), BAM has been frequently called-in by the Berlin Traffic Association (BVG) to carry out root-cause analyses of the Berlin suburban train line (Frahm, 1902), reported in Helmerich and Herter (1999), Helmerich (2000), Nega and Winkler (1998), Helmerich et al. (2002) and Herter et al. (2002). This was also the case in the 1990s, when BVG-inspectors found cracks in hanging, barrel-like shaped ballast plates of the Berlin underground steel viaducts during regularly scheduled inspections. Cracks were located parallel to the riveted connection between the ballast plates and the upper chord of the viaduct cross girder steel profiles. For safety reasons, the operator BVG immediately stopped the cracks by means of drilling stop holes at the crack tips. As intermediate measures, longitudinal steel profiles were spanned below the rail axes between the cross girders affected to stabilize the track in longitudinal direction. The inspection period was shortened from years to few weeks. BAM was mandated to measure strains under regular train traffic to analyze the cause of the cracks. Strains were measured in identical connections as the damaged details, which did not suffer from cracks at the time of the measurement. The traffic-induced strain cycles and thus the resulting strain differences in the questionable cross sections were higher than expected and resulted in stresses of max. 85.8 MPa. Calculations showed that the credible remaining fatigue life for this particular structural detail was exceeded after 68 years according to nowadays standards. Extensive discussions, further field and laboratory tests followed to develop a rehabilitation plan for retrofitting the structure with minimum interference of the traffic. Finally, a method with minimum intervention to the structure was elaborated by a consortium of the operator BVG, BAM and producers based on further laboratory and field tests at BAM. Now, the viaduct is saved for the future. KW - Riveted viaducts KW - Fatigue cracks KW - Strain measurement KW - Rehabilitation KW - Non-ballasted track PY - 2014 DO - https://doi.org/10.1016/j.engfailanal.2014.03.003 SN - 1350-6307 SN - 1873-1961 VL - 43 IS - Special Issue 'A Tribute to Prof. A. Martens' SP - 150 EP - 170 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-30897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hong, Shuxian A1 - Lai Wai-Lok, Wallace A1 - Wilsch, Gerd A1 - Helmerich, Rosemarie A1 - Helmerich, R. A1 - Günther, Tobias A1 - Wiggenhauser, Herbert T1 - Periodic mapping of reinforcement corrosion in intrusive chloride contaminated concrete with GPR JF - Construction and building materials N2 - This paper presents an experimental effort for developing a novel reinforcement corrosion monitoring technique based on Ground Penetrating Radar (GPR). Experiments were carried out to periodically monitor the accelerated reinforcement corrosion process with GPR. The data were processed in both time and time–frequency domains to investigate the tendencies of GPR signal attribute changes related with corrosion, moisture and chloride contamination. Data processing methods were proposed to visualize the reinforcement corrosion and chloride distribution with target specified signal attribute mapping. Half-Cell Potential (HCP) and Laser-Induced Breakdown Spectroscopy (LIBS) methods were employed to verify the GPR observations. KW - Reinforcement corrosion KW - Chloride contamination KW - Periodic monitoring KW - Ground penetrating radar PY - 2014 DO - https://doi.org/10.1016/j.conbuildmat.2014.06.019 SN - 0950-0618 VL - 66 SP - 671 EP - 684 PB - Elsevier Science CY - Amsterdam AN - OPUS4-31397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Milmann, Boris A1 - Wöstmann, Jens A1 - Röllig, Mathias A1 - Kind, Thomas A1 - Lai, W. T1 - Qualitätssicherung für textilfaserverstärkten Beton JF - Tudalit-Magazin T2 - 5. Anwendertagung Textilbeton CY - Friedrichshafen, Germany DA - 2013-09-24 KW - Textilfaserverstärkter Beton KW - Zerstörungsfreie Prüfung KW - Ultraschall-Echo KW - Radar-Echo PY - 2013 VL - 9 SP - 22 AN - OPUS4-29512 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Bien, J. T1 - 100 Jahre Kaiserbrücke/Grunwaldzki-Brücke in Wroclaw (Polen) JF - Stahlbau KW - Zustandsbewertung KW - Brückenmessung KW - Altstahl KW - Baugeschichte PY - 2012 DO - https://doi.org/10.1002/stab.201201524 SN - 0038-9145 SN - 1437-1049 SN - 0932-6375 VL - 81 IS - 2 SP - 156 EP - 159 PB - Ernst CY - Berlin AN - OPUS4-25803 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Bien, J. A1 - Kaminski, T. A1 - Bernardini´, G. T1 - Multi-tool inspection and numerical of an old masonry arch bridge JF - Structure and infrastructure engineering N2 - Complex special inspection of an old masonry arch bridge according to the Guideline on Inspection and Condition Assessment of Railway Bridges and numerical analysis of the structure are presented. The guideline summarises recommendations for the step-by-step investigation of railway bridges applying enhanced methods developed during the EU-funded project Sustainable Bridges. For the investigation of the arch barrel, the ballast parameters and the inner structure of the backfill behind the arch barrel a number of various advanced non-destructive and minor-destructive testing methods were applied. Deformation of the structure during load tests was measured using three independent measuring systems: laser vibrometer, LVDT and microwave radar. Results of calculations performed with 2D and 3D models based on FEM are compared with the field load tests. Sensitivity of the ultimate load of the structure to investigated parameters is studied in FE model. Some general conclusions according to methods of testing and modelling of masonry arch bridges are presented and discussed. KW - Masonry bridges KW - Non-destructive testing KW - Bridge inspection KW - Finite element method PY - 2012 SN - 1573-2479 VL - 8 IS - 1 SP - 27 EP - 39 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-27425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie T1 - Brücken aus der Preußisch-Königlichen Hütte Malapane in Malapane JF - Stahlbau KW - Brücken KW - Gusseisen KW - Rezension KW - Historische Hütte KW - Älteste gusseiserne Brücken PY - 2010 DO - https://doi.org/10.1002/stab.201002191 SN - 0038-9145 SN - 1437-1049 SN - 0932-6375 VL - 79 IS - 12 SP - 943 EP - 946 PB - Ernst CY - Berlin AN - OPUS4-22941 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Bien, J. A1 - Kaminski, T. A1 - Bernardini, G. T1 - Multi-tool inspection and numerical analysis of an old masonry arch bridge JF - Structure & infrastructure engineering N2 - Complex special inspection of an old masonry arch bridge according to the Guideline on Inspection and Condition Assessment of Railway Bridges and numerical analysis of the structure are presented. The guideline summarises recommendations for the step-by-step investigation of railway bridges applying enhanced methods developed during the EU-funded project Sustainable Bridges. For the investigation of the arch barrel, the ballast parameters and the inner structure of the backfill behind the arch barrel a number of various advanced non-destructive and minor-destructive testing methods were applied. Deformation of the structure during load tests was measured using three independent measuring systems: laser vibrometer, LVDT and microwave radar. Results of calculations performed with 2D and 3D models based on FEM are compared with the field load tests. Sensitivity of the ultimate load of the structure to investigated parameters is studied in FE model. Some general conclusions according to methods of testing and modelling of masonry arch bridges are presented and discussed. KW - Masonry bridges KW - Non-destructive testing KW - Bridge inspection KW - Finite element method PY - 2010 DO - https://doi.org/10.1080/15732471003645666 SN - 1573-2479 SN - 1744-8980 IS - NSIE_A_465075 SP - 1 EP - 13 PB - Taylor & Francis CY - London AN - OPUS4-22838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kühn, B. A1 - Helmerich, Rosemarie A1 - Nussbaumer, A. A1 - Günther, H.-P. A1 - Herion, S. T1 - Beurteilung bestehender Stahltragwerke: Empfehlungen zur Abschätzung der Restnutzungsdauer JF - Stahlbau N2 - Die zunehmende Bedeutung der Nachhaltigkeit im Bauwesen wird in Zukunft das Bauen im Bestand gegenüber Neubauten in den Vordergrund rücken. Dies gilt auch für den Brückenbau, wo das Qualitätsmanagement seit langem Brücken von ihrem Entstehungsgang über den Betrieb bis in die Entsorgung begleitet. Die starke Vergrößerung der Frachtvolumina für Straße und Schiene und die zunehmende Überalterung des Brückenbestandes fragen danach, ob die bestehenden Brücken für die veränderten Betriebsbedingungen noch geeignet sind und wie sie und ob sie dafür instandgesetzt werden könnten. Für die erforderlichen Instandhaltungs- und Instandsetzungsmaßnahmen oder einen eventuellen Ersatz durch einen Neubau ist aber die Frage der Restnutzungsdauer von entscheidender Bedeutung. Es ist daher nicht von ungefähr, dass sich Baulast-träger auf nationaler und internationaler Ebene frühzeitig zusammengetan haben, um nach geeigneten Methoden der Bestimmung der Sicherheit und Restnutzungsdauer bestehender Brücken zu forschen. Auch die internationalen technisch-wissenschaftlichen Verbände wie EKS und fib sowie die Standard-Organisationen ISO und CEN sind der Frage eines internationalen Austauschs und der Vereinheitlichung der Methoden nachgegangen. Für Stahlbrücken hat insbesondere das technische Komitee6 - Ermüdung - der EKS Anregungen aufgegriffen, aus den verschiedenen nationalen Erfahrungen und dem vorhandenen Wissen technische Empfehlungen für die Beurteilung bestehender Stahlbrücken zu entwickeln [1], die sich als Grundlage für die von CEN/TC 250 - das CEN-Komitee für die Bearbeitung der Eurocode - geplante Erweiterung der Eurocode zur Instandhaltung und Instandsetzung des Brückenbestandes eignen. Das Ergebnis ist ein technisch-wissenschaftlicher Bericht, der im Rahmen der Zusammenarbeit der europäischen Kommission (DG-Research - Joint Research Centre JRC) mit der EKS als Basispapier für eine zukünftige Eurocode-Erweiterung veröffentlicht wurde und schon jetzt als Empfehlung für eine Vorgehensweise nach dem Stand der Technik verwendet werden kann. Der vorliegende Beitrag behandelt die Grundzüge dieses Berichtes [1], der vom e-bookshop der Kommission kostenfrei herunter geladen werden kann. PY - 2008 DO - https://doi.org/10.1002/stab.200810072 SN - 0038-9145 SN - 1437-1049 SN - 0932-6375 VL - 77 IS - 8 SP - 595 EP - 607 PB - Ernst CY - Berlin AN - OPUS4-17893 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Algernon, Daniel A1 - Streicher, Doreen A1 - Wiggenhauser, Herbert T1 - Bridge Inspection and Condition Assessment in Europe JF - Transportation research record N2 - The European infrastructure asset has developed historically and is characterized by nation-specific construction processes. Inspection, condition assessment, and maintenance procedures differ from country to country. Because of historical and political circumstances, national infrastructure assets are maintained at different levels, too. Since the budget for maintaining the bridge infrastructure less and less meets the demands of a growing bridge stock, bridge inspection, maintenance, and life-cycle considerations gain higher importance. The need exists to develop effective diagnosis tools for early detection of construction faults, defects, and deterioration processes during inspection, to keep the bridge infrastructure at an acceptable level, from structural safety and economic viewpoints. An overview on the latest research projects and integrated bridge management systems in Europe is given. The potentials of nondestructive testing (NDT) are presented, with special focus on technical advances of NDT applications to reinforced concrete (RC) and posttensioned concrete bridges. Although NDT is not regularly integrated in these processes, the application brings valuable information on the current condition of the inner structure in called-in special inspections. NDT-automation and the application of imaging echo methods, combined with advanced data processing, produce a surprising level of information about the inner structure of massive RC slabs up to a depth of about 60 cm. Detected inhomogeneity and scatterers of acoustic or electromagnetic waves can be visualized in vertical or horizontal slices through the structure or animations. The fusion of different three-dimensional data sets of processed data improves the interpretability and accuracy of the results. KW - Category IIIC PY - 2008 DO - https://doi.org/10.3141/2044-04 SN - 0361-1981 VL - 2044 SP - 31 EP - 38 PB - National Research Council CY - Washington, DC AN - OPUS4-18037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -