TY - JOUR A1 - Bartholmai, Matthias A1 - Strangfeld, Christoph A1 - Van Bocxlaer, A. T1 - RFID-Sensor-Transponder in Beton N2 - Sensor-Transponder-Lösung der BAM ermöglicht automatisiertes Brückenmonitoring und Predictive Maintenance und detektiert Korrosion in Beton. KW - RFID-Sensorsysteme KW - Bauteilintegrierte Sensoren KW - Betonkorrosion KW - Structural health monitoring PY - 2017 SN - 1860-5907 VL - 2017 IS - 5 SP - 46 EP - 49 PB - Verlag & Freie Medien, Lüneburg CY - Lüneburg AN - OPUS4-40873 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Oesch, Tyler T1 - In-situ analysis of water transport in concrete completed using X-ray computed tomography N2 - The water-transport characteristics of concrete have a major impact on its resistance to damaging chemical processes such as Alkali-Silica-Reaction (ASR). Water transport in samples of damaged and undamaged concrete was measured using in-situ CT. The resulting measurements of water-front movement relative to time and the change in 3D-moisture distribution within the samples, are needed for calibration and validation of water-transport numerical models. T2 - 3rd International Conference on Tomography of Materials and Structures CY - Lund, Sweden DA - 26.06.2017 KW - X-ray computed tomography (CT) KW - In situ KW - Water transport KW - Alkali-silica-reaction (ASR) PY - 2017 AN - OPUS4-40876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kühne, Hans-Carsten T1 - Sicherheitskonzepte im Massivbau - Grundlagen bei der Bemessung und Ausführung von Stahlbeton- und Spannbetonbauwerken N2 - Der Anhang I der Bauproduktenverordnung EU 305/2011 definiert die an ein Bauwerk gestellten Grundanforderungen: „Bauwerke müssen als Ganzes und ihren Teilen für deren Verwendungszweck tauglich sein, wobei insbesondere der Gesundheit und der Sicherheit der während des gesamten Lebenszyklus der Bauwerke involvierten Personen Rechnung zu tragen ist“. Dementsprechend ist mit einer angemessenen Zuverlässigkeit ein mögliches Versagen des Bauwerkes auszuschließen und der vorgegebene Nutzungszweck ist für die vorgesehene Nutzungsdauer unter Berücksichtigung von wirtschaftlichen Gesichtspunkten zu gewährleisten. Anhand der vorliegenden Präsentation wird für den Bereich des Massivbaus ein Überblick über die maßgebenden Normen auf nationaler und europäischer Ebene gegeben. Dies beinhalt relevante Normen für die Bemessung von Bauwerken sowie die Anforderungen an die verwendeten Baustoffe und deren Überwachung. T2 - Informationveranstaltung der BAM CY - BAM, Berlin, Germany DA - 23.06.2017 KW - Sicherheitskonzept KW - Massivbau KW - Bemessung KW - Ausführung KW - Überwachung PY - 2017 AN - OPUS4-40908 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolf, A. T. A1 - Recknagel, Christoph A1 - Wenzel, Norman A1 - Sitte, S. T1 - Structural Silicone Glazing: Life Expectancy of more than 50 Years? N2 - Structural Silicone Glazing (SSG) is a curtain walling method that utilizes silicone sealants to adhere glass, ceramic, metal or composite panels to supporting framing members by means of a peripheral adhesive joint. In SSG curtain walls, silicone sealants serve not only as a weather seal, but also act as a structural bonding element, eliminating the need for exterior retainers and covers. The paper discusses some essential findings of two recent research studies on the durability and service life of structural silicone glazing sealants and structures. The first study demonstrates, that specimens of a first generation 2-part silicone sealant taken from a SSG façade after 23+2 years of real life successfully passed the European ETAG002-1 performance criteria for residual strength. In a second study, a new performance-based durability test method was developed in partnership with the Federal Institute for Materials Research Berlin/Germany (BAM). This method is based on simultaneously exposing system test specimens to artificial weathering and complex, multiaxial mechanical loadings. 2-part structural silicone sealants of the first and of the second generation where subjected to this test, which is considered to correspond to an anticipated service life of 50 years. T2 - Glass Performance Days 2017 CY - Tampere, Finland DA - 28.06.2017 KW - Structural Sealant Glazing KW - Silicone adhesive KW - Durability KW - Climatic simulation KW - Artificial weathering KW - Mechanical loading PY - 2017 SN - 978-952-5836-06-6 SP - 338 EP - 345 PB - Glaston Finland Oy CY - Tampere, Finland AN - OPUS4-41288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Larcher, M. A1 - Arrigoni, A. A1 - Bedon, C. A1 - van Doormaal, A. A1 - Haberacker, C. A1 - Hüsken, Götz A1 - Millon, O. A1 - Saarenheimo, A. A1 - Solomos, G. A1 - Thamie, L. A1 - Valsamos, G. A1 - Williams, A. A1 - Stolz, A. T1 - Recommendations for a new generation of standards for testing numerical assessment of blast-loaded glass windows N2 - The determination of the blast protection level of civil engineering buildings components against explosive effects represents a topic of crucial importance, in current practice. However, some key aspects of blast resistant structures design have been only marginally considered in the last decade, and currently still require appropriate regulations. This is especially true in the case of windows and facades, where the intrinsic material brittleness is the major influencing parameter for blast-resistant assemblies. While blast assessment of buildings and systems is usually achieved by means of experimental investigations, as well as numerical simulations, general regulations and guidelines are currently missing. In this regard, the European Reference Network for Critical Infrastructure Protection (ERNCIP) Thematic Group “Resistance of Structures to Explosion Effects” attempts to develop guidelines and recommendations aimed to harmonise test procedures in experimental testing of glass windows under blast, as well as standardized approaches for their vulnerability assessment via numerical modelling. In this paper, major Thematic Group outcomes and next challenges are briefly summarized. T2 - International Conference on Structural and Mechanical Engineering for Security and Prevention - ICSMESP 2017 CY - Prague, Czech Republic DA - 14.06.2017 KW - Blast protection KW - Blast loaded glass windows KW - Experimental testing KW - Finite element numerical modelling KW - Standardisation PY - 2017 DO - https://doi.org/10.4028/www.scientific.net/KEM.755.121 SN - 1662-9795 VL - 755 SP - 121 EP - 130 PB - Trans Tech Publications Inc. CY - Zurich, Switzerland AN - OPUS4-41927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Galvanic Anode systems in Concrete structures and their performance part 1 N2 - Corrosion of reinforcement is one of the major reasons in questioning the sturdiness of building structures. The application of cathodic protection techniques plays a big role in controlling the corrosion process to ensure a longer service life of building structures. This systematic study compares the efficiency and durability of various discrete galvanic zinc anode systems available in the current market using different criteria for measuring efficiencies such as potential measurements, electrolyte resistance measurements and several polarization methods to determine the polarizability of the anodes. Results to validate the performance of long-time exposure of discrete zinc anodes in the concrete medium are already shown in 2021. Now the results of analyzing the phase boundary between mortar and anodes by using 3D computer tomography are shown, as also the field application at large-scale specimens where the potential distribution and the current were investigated. T2 - Eurocorr 2023 CY - Brussels, Belgium DA - 27.08.2023 KW - Corrosion KW - Corrosion Protection PY - 2023 AN - OPUS4-58169 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Potential Mapping at Concrete Structures N2 - Electrochemical potential mapping is a recognized technique for the localization of corroding reinforcing steels. Areas of corroding reinforcement steel can be located in a non-destructive manner by means of this procedure. Half‐cell potential measurements are used in order to detect chloride‐induced corrosion. However, it is not recommended in order to assess the risk of carbonation‐induced corrosion. For this purpose, determining the carbonation depth and the concrete cover appears more appropriate. The content of this specification exclusively refers to the application of mobile, local variable reference electrodes, which are only placed on the concrete surface while measuring. The technique distinguishes itself thereby from the range of corrosion monitoring systems with stationary installed reference electrodes and sensor systems, respectively, whereby it is possible to continuously track measurements within the area of the installed electrodes. However, these methods are not dealt with in this specification. T2 - NDT&E Workshop 2024 CY - Baruth/Mark, Germany DA - 03.07.2024 KW - Corrosion KW - Potential mapping PY - 2024 AN - OPUS4-60584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Boschmann Käthler, C. A1 - Ebell, Gino A1 - Keßler, S. A1 - Schiegg, Y. A1 - Dauberschmidt, C. A1 - Angst, U. M. T1 - A comparison of methods to assess the resistance of reinforcing steel against chloride‐induced corrosion in concrete: Particular consideration of 12% chromium steel N2 - The critical chloride content C(crit) is an indicator for the corrosion resistance of reinforcing steels in concrete. In this article, several experimental methods for determining the critical chloride content C(crit) of mild and an alloyed (12% Cr) steel in cementitious materials are compared. The methods used include accelerated polarization tests and tests using more natural (unpolarized) conditions in which chloride ingress occurs by diffusion and capillary uptake. The advantages and disadvantages of the methods are discussed, in particular, with the objective of reaching a compromise between applicability to practice and feasibility in laboratory testing. KW - Chloride‐induced corrosion KW - Critical chloride content KW - Reinforced concrete KW - Testing methods PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529751 DO - https://doi.org/10.1002/maco.202112609 SN - 1521-4176 SP - 1 EP - 20 PB - Wiley-VCH CY - Weinheim AN - OPUS4-52975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seyhan, E. A1 - Ebell, Gino A1 - Jimenez, D. A1 - Chavez, J. A1 - Sanchez Alvarez, G T1 - Evaluation of SACI performance on reinforced concrete structures N2 - Surface applied corrosion inhibitors (SACI) are widely used to mitigate corrosion process of steel reinforcement in concrete. But they remain controversial as to their effectiveness and the ability to compare materials from different manufacturers and technologies. They are applied onto the surface of hardened concrete and penetrate towards steel reinforcement. This paper discusses the corrosion inhibition performances of dual-phase surface applied corrosion inhibitor and the efficiency of the corrosion inhibitor is assessed by selected testing procedures in BAM laboratories. T2 - ACHE 2022 CY - Santander, Spain DA - 20.06.2022 KW - Corrosion KW - Inhibitor PY - 2022 AN - OPUS4-55095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schalau, Sebastian A1 - Habib, Abdel Karim T1 - Atmospheric wind field modelling with OpenFOAM for near-ground gas dispersion N2 - CFD simulations of near-ground gas dispersion depend significantly on the accuracy of the wind field. When simulating wind fields with conventional RANS turbulence models, the velocity and turbulence profiles specified as inlet boundary conditions change rapidly in the approach flow region. As a result, when hazardous materials are released, the extent of hazardous areas is calculated based on an approach flow that differs significantly from the boundary conditions defined. To solve this problem, a turbulence model with consistent boundary conditions was developed to ensure a horizontally homogeneous approach flow. Instead of the logarithmic vertical velocity profile, a power law is used to overcome the problem that with the logarithmic profile, negative velocities would be calculated for heights within the roughness length. With this, the problem that the distance of the wall-adjacent cell midpoint has to be higher than the roughness length is solved, so that a high grid resolution can be ensured even in the near-ground region which is required to simulate gas dispersion. The evaluation of the developed CFD model using the German guideline VDI 3783/9 and wind tunnel experiments with realistic obstacle configurations showed a good agreement between the calculated and the measured values and the ability to achieve a horizontally homogenous approach flow. KW - OpenFOAM KW - Gas dispersion KW - Atmospheric boundary layer KW - Turbulence model PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-539095 DO - https://doi.org/10.3390/atmos12080933 VL - 12 IS - 8 SP - 933 PB - MDPI AN - OPUS4-53909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Salari, Farid A1 - Zocca, Andrea A1 - Bosetti, Paolo A1 - Hlaváček, Petr A1 - Italiano, Antonino A1 - Gobbin, Filippo A1 - Colombo, Paolo A1 - Kühne, Hans-Carsten A1 - Sglavo, Vincenzo M. T1 - Powder-bed 3D printing by selective activation of magnesium phosphate cement: Determining significant processing parameters and their effect on mechanical strength N2 - The present work addresses powder bed binder jetting additive manufacturing by selective magnesium phosphate cement activation. Despite the potential of this technology to aid the digitalization of the construction industry, the effect of processing parameters on the mechanical performance of printed materials has not yet been studied to generate a guideline for the further development of the technology. Statistical methodologies were used to screen the effect of four printing process parameters (printing speed, layer thickness, raster angle, and build direction on flexural and compressive strength). As the exploited technology works with constant fluid pressure, the physical interpretation of the effect of each factor can be considered taking into account the interactions between the binder materials in the powder bed. Analysis of variance (ANOVA) indicated that printing speed and layer thickness significantly affect mechanical performances. Furthermore, the layout of samples for the printing process is preferable to be parallel the printhead movement. An anisotropic behavior was observed, and the samples subjected to compressive forces parallel to the layer plane possessed lower strength values. This effect can be interpreted as a result of a weak area of low density in between layers, leading to a pronounced delamination under compression. Even though the strength of the printed material is not suitable for a structural concrete, it can be marginally improved by design of experiment and optimized for non-structural applications, such as for porous artificial stone. Design of experiment coupled with ANOVA methods can be used in the future to support the development of novel material mixtures, thus expanding the fields of application of this novel additive manufacturing technology. KW - Concrete 3D-printing KW - Particle-bed binder jetting KW - Design of experiment PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601654 DO - https://doi.org/10.1016/j.oceram.2024.100609 VL - 18 SP - 1 EP - 11 PB - Elsevier B.V. AN - OPUS4-60165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Villani, P. A1 - Unger, Jörg F. A1 - Weiser, M. T1 - Adaptive Gaussian process regression for Bayesian inverse problems N2 - We introduce a novel adaptive Gaussian Process Regression (GPR) methodology for efficient construction of surrogate models for Bayesian inverse problems with expensive forward model evaluations. An adaptive design strategy focuses on optimizing both the positioning and simulation accuracy of training data in order to reduce the computational cost of simulating training data without compromising the fidelity of the posterior distributions of parameters. The method interleaves a goal-oriented active learning algorithm selecting evaluation points and tolerances based on the expected impact on the Kullback-Leibler divergence of surrogated and true posterior with a Markov Chain Monte Carlo sampling of the posterior. The performance benefit of the adaptive approach is demonstrated for two simple test problems. T2 - Algoritmy 2024 - Central-European Conference on Scientific Computing CY - Vysoké Tatry, Slovakia DA - 15.03.2024 KW - Gaussian process regression KW - Bayesian inverse problems KW - Surrogate models KW - Parameter identification KW - Active learning PY - 2024 SP - 1 EP - 10 PB - Slovak University of Technology CY - Bratislava AN - OPUS4-60738 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Moisture testing and mapping N2 - Most building materials are porous and hydrophilic. Thus, for condition assessment and damage detection a determination of the material moisture is required. In this lecture, a short overview is given regarding moisture transport in porous media in the hygroscopic range. Then, several non-destructive measurement techniques are introduced. Here, the focus lies on their practical application and limitations. T2 - NDT&E Advanced Training Workshop CY - Berlin, Germany DA - 03.07.2024 KW - Building materials KW - Concrete KW - Material moisture KW - Moisture measurement techniques KW - Moisture transport PY - 2024 AN - OPUS4-60605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hothan, Sascha T1 - Forschungsprojekt "INSIST" N2 - Der Vortrag zeigt den Bearbeitungsstand des Forschungsvorhabens "Entwicklung eines Verfahrens zur in situ Bewertung des Feuerwiderstands von bestehenden Stahlkonstruktionen mit reaktiven Brandschutzsystem (RBS)" (INSIST). Die Entwicklung und der Bau eines Geräteprototyps wurden vorgenommen und ein Konzept zur Kalibration erarbeitet. Die bisherigen Untersuchungen belegen, dass das Verfahren Ergebnisse liefert, die denen konventioneller Brandversuche im untersuchten Parameterbereich gleichwertig sind. T2 - Sachverständigenausschuss Reaktive Baustoffe und Beschichtungen -B- (463a) des Deutschen Institutes für Bautechnik CY - Berlin, Germany DA - 13.02.2024 KW - INSIST KW - In situ Bewertung KW - RBS PY - 2024 AN - OPUS4-60777 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meng, Birgit T1 - Wissensbasierte Digitalisierung von betontechnologischen Materialdaten N2 - Die sprunghaft zunehmende Wichtigkeit von FAIR- und Open-Data für die Qualitätssicherung, aber auch für die Nachnutzbarkeit von Daten und den Erkenntnisfortschritt führt zu enormem Flandlungsbedarf in Forschung und Entwicklung. Damit verbunden laufen derzeit vielfältige, ambitionierte Aktionen, z. B. bezüglich der Erstellung von Ontologien und Wissensgraphen. Das Knowhow entwickelt sich rasant, die Ansätze zur Implementation entstehen in verschiedenen Fachwelten bzw. mit unterschiedlichen Zielsetzungen parallel, so dass recht heterogene Herangehensweisen resultieren. Diese Veröffentlichung fokussiert auf Arbeiten, die derzeit als möglichst ganzheitlicher Ansatz für Materialdaten im Rahmen der Digitalisierungsinitiative „Plattform MaterialDigital" vorangetrieben werden. Die Autoren bearbeiten baustoffbezogene Aspekte im Verbundprojekt „LeBeDigital - Lebenszyklus von Beton". Zielsetzung ist die digitale Beschreibung des Materialverhaltens von Beton über den kompletten Herstellungsprozess eines Fertigteils mit einer Integration von Daten und Modellen innerhalb eines Workflows zur probabilistischen Material- und Prozessoptimierung. Es wird über die Vorgehensweise und die dabei gewonnenen Erfahrungen berichtet, nicht ohne den Blick auf die oft unterschätzte Komplexität der Thematik zu lenken. T2 - Ibausil 2023 CY - Weimar, Germany DA - 13.09.2023 KW - Beton KW - Digitalisierung KW - Datenmanagement KW - FAIR-Prinzip KW - Metadaten KW - Ontologie KW - Wissensgraph PY - 2023 AN - OPUS4-60964 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Moisture diffusion affected by the Knudsen effect in temporal changing pore networks N2 - Almost all building materials in civil engineering have an open porosity and interact with or are affected by the environmental conditions. Structures might suffer from effects such as moisture adsorption, carbonation, corrosion, penetration of salt ions and chemical substances, etc. In the hygroscopic range, these processes are mostly driven by diffusion. Due to the confinement of small pores ( 1 m), the Knudsen effect reduces the molecular diffusion. This reduction can become more significant in case of temporal changing pore systems because of physisorption of water vapor, carbonation, or chemisorption. In this study, unstabilised earth blocks and earth masonry are investigated. In a first step, the pore size distribution of the blocks is measured and sorption isotherms are recorded in experiments. Besides the ordinary physisorption, the involved clay minerals undergo swelling or shrinking due to chemisorption. The following two effects must be considered: first, the reduction of the available pore space by the adsorbed water layer. For this, the Hillerborg sorption theory is used, which is a combination of the well-known Brunauer-Emmett-Teller sorption theory and the Kelvin equation. This allows the computation of adsorbed water layers even in curved pore geometries. Second, the variation of the initial pore size distribution due to chemisorption needs to be modelled. Based on these two models, the effective diffusion coefficient can be predicted. For validation, arrays of relative humidity sensors were embedded into a free-standing earth masonry wall. This monitoring was carried out over more than a year to have a broad variety of environmental conditions and was located in Berlin, Germany. The prediction of the effective diffusion coefficient can also be transferred to other processes and allows the investigation of materials having temporarily changing pore systems. Examples are the carbonation of cementitious materials, alkali silica reaction, calcium leaching of long-lasting structures, etc. This effect becomes most prominent in the meso-pore range and might alter the effective diffusion coefficient by more than 100 %. T2 - 4th International Congress on Materials & Structural Stability CY - Rabat, Morocco DA - 08.03.2023 KW - Earth masonry KW - Material moisture KW - Molecular diffusion KW - Chemisoprtion KW - Knudsen effect KW - Physisorption PY - 2023 AN - OPUS4-57140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sperlich, Tim A1 - Häßler, Dustin A1 - Stelzner, Ludwig A1 - Hothan, Sascha T1 - In situ Prüfmethode zur Untersuchung des Feuerwiderstands von bestehenden Stahlkonstruktionen mit reaktivem Brandschutzsystem N2 - Der Beitrag beschreibt die Entwicklung eines neuartigen in situ Nachweisverfahrens zur Beurteilung des Feuerwiderstandes von bestehenden Stahlkonstruktionen mit gealtertem reaktivem Brandschutzsystem (RBS). Derzeit ist ein solcher Nachweis ausschließlich anhand eines Bauteilbrandversuchs möglich. Hierzu muss ein Bauteil aus der Bestandskonstruktion entnommen und einer zerstörenden Brandprüfung unterzogen werden. In Zusammenhang mit der Dauerhaftigkeitsbewertung von RBS für Zeiträume von mehr als 10 Jahren besteht in der Praxis vermehrt der Bedarf an einem minimal invasiven Prüfverfahren, mit dessen Hilfe sich direkt am Bestandsbauwerk die tatsächlich vorhandene Leistungsfähigkeit des gealterten RBS überprüfen lässt. Durch einen erfolgreichen Funktionsnachweis wäre eine Weiternutzung der Bestandkonstruktion bei Aufrechterhaltung des bestehenden Sicherheitsniveaus möglich. T2 - Symposium Heißbemessung - Structural Fire Engineering CY - Braunschweig, Germany DA - 05.09.2023 KW - Brandschutz KW - Stahlbau KW - reaktives Brandschutzsystem KW - Prüfmethode KW - Brandversuch PY - 2023 SP - 1 EP - 16 PB - TU Braunschweig CY - Braunschweig AN - OPUS4-58180 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sperlich, Tim T1 - In situ Prüfmethode zur Untersuchung des Feuerwiderstands von bestehenden Stahlkonstruktionen mit reaktivem Brandschutzsystem N2 - Der Beitrag beschreibt die Entwicklung eines neuartigen in situ Nachweisverfahrens zur Beurteilung des Feuerwiderstandes von bestehenden Stahlkonstruktionen mit gealtertem reaktivem Brandschutzsystem (RBS). Derzeit ist ein solcher Nachweis ausschließlich anhand eines Bauteilbrandversuchs möglich. Hierzu muss ein Bauteil aus der Bestandskonstruktion entnommen und einer zerstörenden Brandprüfung unterzogen werden. In Zusammenhang mit der Dauerhaftigkeitsbewertung von RBS für Zeiträume von mehr als 10 Jahren besteht in der Praxis vermehrt der Bedarf an einem minimal invasiven Prüfverfahren, mit dessen Hilfe sich direkt am Bestandsbauwerk die tatsächlich vorhandene Leistungsfähigkeit des gealterten RBS überprüfen lässt. Durch einen erfolgreichen Funktionsnachweis wäre eine Weiternutzung der Bestandkonstruktion bei Aufrechterhaltung des bestehenden Sicherheitsniveaus möglich. T2 - Symposium Heißbemessung - Structural Fire Engineering CY - Braunschweig, Germany DA - 05.09.2023 KW - Brandschutz KW - Stahlbau KW - Reaktives Brandschutzsystem KW - Prüfmethode KW - Brandversuch PY - 2023 AN - OPUS4-58183 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosenbusch, Sjard Mathis T1 - Mesh-convergence and gradient-enhanced models in blast simulations of concrete structures N2 - Blast experiments on reinforced concrete structures are often limited to small structures and therefore simple shock waves. Such experiments are carried out at the Bundesanstalt für Materialforschung und -prüfung (BAM) and the structural response is investigated using several measuring methods. Complex load scenarios that occur as a result of reflection of the shock wave in larger structures are harder to realise in practice. Numerical simulations for the propagation of the shock wave and the structural response can therefore be an alternative method for the investigation of blast loads on complex structures. For the simulation of concrete under impact and blast loads, several local constitutive models exist that are formulated as plasticity models with softening taken into account by introducing a scalar damage field. Local damage models however often lead to mesh-dependent results which do not converge with mesh refinement. In order to achieve meaningful predictions from numerical experiments, independence from the mesh is needed. In this contribution, the JH2 model (Johnson and Holmquist 1994) with a parameter set for concrete is investigated in a simple blast load scenario. The shockwave is implemented as a simplified Friedlander-curve and the overpressures are applied as a boundary condition for the structural simulation. In order to account for large displacements that can occur during blast loads, an updated Lagrangian formulation is utilised. A Runge-Kutta method with adaptive time stepping is used to advance the solution in time. The open source FEM software FEniCS (Logg et al. 2012) is used together with an implementation of the JH2 model which has been developed at BAM. An extensive convergence analysis with both timestep- and mesh-refinement is carried out to show the mesh dependency. In order to make the results independent of the mesh, possible nonlocal versions of the JH2 model with gradient-enhancement are presented. Since many damage models for concrete share the damage mechanism of the JH2 model, the application of the regularisation methods to more complex material models, like the RHT model (Grunwald et al. 2017), is also discussed. Advantages of a gradient-enhanced formulation to simulate dynamic strength increase of concrete, as suggested in (Häußler-Combe and Kitzig 2009), is discussed as well. T2 - ECCOMAS YIC 2023 CY - Porto, Portugal DA - 19.06.2023 KW - Gradient-Damage KW - Explicit Dynamics KW - Concrete Modeling KW - Mesh Convergence PY - 2023 AN - OPUS4-58717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Bartholmai, Matthias 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 AN - OPUS4-58662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -