TY - CONF A1 - Hüsken, Götz A1 - Brouwers, H.J.H. T1 - The influence of the fines on the early-age behavior of zero-slump concrete T2 - 18. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 2012-09-12 KW - Zero-slump concrete KW - Green-strength KW - Compaction behavior KW - Intensive compaction test PY - 2012 SN - 978-3-00-034075-8 VL - 2 IS - 3.07 SP - 2-0001 - 2-0008 AN - OPUS4-26541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Quercia, G. A1 - Spiesz, P. A1 - Hüsken, Götz A1 - Brouwers, H.J.H. T1 - Chloride intrusion and freeze-thaw resistance of self-compacting concrete with two different nano-SiO2 T2 - 18. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 2012-09-12 KW - Nano-SiO2 KW - Concrete KW - Self compacting KW - Durability KW - Chloride and freeze-thaw KW - Nano-silica PY - 2012 SN - 978-3-00-034075-8 VL - 2 IS - 3.07 SP - 2-0123 - 2-0136 AN - OPUS4-26542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Brouwers, J. T1 - The Influence of the Fines on the Early-Age Behavior of Zero-Slump Concrete T2 - IBAUSIL CY - Weimar, Germany DA - 2012-09-12 PY - 2012 AN - OPUS4-26514 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hüsken, Götz A1 - Brouwers, H.J.H. T1 - On the early-age behavior of zero-slump concrete N2 - This paper presents experimental investigations and analyses on the early-age-behavior of zero-slump concrete, such as compaction behavior and green-strength. First, the influence of the granulometric properties of the fines is discussed in detail. For this purpose, the early-age behavior of two different fines (quartz flour and fly ash) is investigated by means of the intensive compaction test (IC-test). The tests on the influence of the fines focus on effects caused by differences in the particle shape and the use of a plasticizing admixture. The conducted tests on the compaction behavior of the fines and their corresponding green-strength are extended to continuously graded granular mixes. Here, the influence of optimized particle packing on the early-age behavior is presented and a comparison on the basis of the aforementioned quartz flour and fly ash is made. In this consideration, experimental investigations on the early-age behavior of a zero-slump concrete mix and possible effects on the hardened concrete properties are included. KW - Zero-slump concrete (A) KW - Green-strength (C) KW - Compaction behavior (A) KW - Intensive compaction test (C) PY - 2012 U6 - https://doi.org/10.1016/j.cemconres.2011.11.007 SN - 0008-8846 SN - 1873-3948 VL - 42 IS - 3 SP - 501 EP - 510 PB - Pergamon Press CY - New York, NY AN - OPUS4-26078 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Quercia, G. A1 - Hüsken, Götz A1 - Brouwers, H.J.H. T1 - Water demand of amorphous nano silica and its impact on the workability of cement paste N2 - This paper addresses the characterization of six different amorphous silica samples with respect to their application in cement paste. Different mixes are compared and analyzed using the mini spread-flow test. Also the granular properties, different void fraction states of packing and distribution moduli q are analyzed and compared using a mix design tool. A deformation coefficient is derived from the spread-flow test, which correlates with the value of specific surface area computed from the particle size distribution, and intrinsic density of the samples. Finally, the thickness of a constant water layer of 25 nm around the particles is computed at the onset of flowing. The granular analysis demonstrated that it is possible to decrease the water demand of the cement paste when nanoparticles are added and the resulting grading follows the modified Andreasen and Andersen curve (q = 0.5), and the concentration of nano silica is less than 5% bwoc. KW - Nano silica (D) KW - Particle size distribution (B) KW - Surface area (B) KW - Water demand (A) KW - Workability (A) PY - 2012 U6 - https://doi.org/10.1016/j.cemconres.2011.10.008 SN - 0008-8846 SN - 1873-3948 VL - 42 IS - 2 SP - 344 EP - 357 PB - Pergamon Press CY - New York, NY AN - OPUS4-26079 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Weise, Frank A1 - Hüsken, Götz T1 - Ringversuch zum statischen Spaltzugversuch nach AL Sp-Beton N2 - Für die rechnerische Dimensionierung der Betondecken im Oberbau von Verkehrsflächen für den Neubau sowie die Erneuerung nach RDO-Beton 09 ist die statische Spaltzugfestigkeit an der unteren und oberen Bohrkernscheibe entsprechend der Vorgaben der AL Sp-Beton zu bestimmen. Aufgrund der unzureichenden Kenntnis der Präzision dieses Prüfverfahrens wurden, basierend auf dem Entwurf des FGSV-Merkblatts zur statistischen Auswertung von Prüfergebnissen, mit einem breit aufgestellten Ringversuch die statistischen Kennwerte an Labor- und Bestandsbetonen unter Vergleich- und Wiederholbedingungen ermittelt. Zur möglichst guten statistischen Absicherung nahmen an dem Ringversuch dreizehn erfahrene Prüfstellen teil, die vorab einem Audit unterzogen wurden. Zur Abdeckung des vielschichtigen Einsatzes des Prüfverfahrens erfolgte der Ringversuch an acht Prüflosen, die sowohl die Erst-/ Eignungsprüfung und Übereinstimmungskontrolle bei Neubaumaßnahmen, als auch die Restsubstanzbewertung von Betonfahrbahnplatten berücksichtigen. Zur Bewertung des Materialeinflusses wurde zusätzlich ein Prüflos mit Labormörtel untersucht. Die Probenvorbereitung erfolgte zentral an der BAM. Zur Sicherstellung einheitlicher Prüfbedingungen bei den Prüfstellen wurde zusätzlich eine detaillierte Standardarbeitsanweisung erarbeitet, die partiell bereits Eingang in das Normenwerk gefunden hat. Bei der Plausibilitätsprüfung aller prüflosspezifischen Einzelwerte der Spaltzug- und Druckfestigkeit wurden vereinzelt sowohl Ausführungsfehler als auch Übertragungs- und Tippfehler festgestellt. Der sich anschließende Lilliefors-Test zeigt, dass die ermittelten Einzelwerte bis auf wenige Aus-nahmen normalverteilt sind und damit die Voraussetzungen für die statistische Auswertung gegeben sind. Mittels grafischer Darstellung der Mandel’s h- und k-Werte wurden die Auffälligkeiten hinsichtlich der Mittelwerte und Varianzen prüflosspezifisch für die einzelnen Prüfstellen visualisiert und anschließend einige von ihnen mittels Grubbs- und Cochran-Test als Ausreißer identifiziert. Nach Ausreißerelimination wurde mit dem klassischen Verfahren bei der Spaltzugfestigkeit der geringste Variationskoeffizient unter Vergleich- und Wiederholbedingungen bei der Erst-/Eignungsprüfung mit 6,2 und 6,4 Prozent ermittelt. Bei einer Verminderung des Materialeinflusses durch die Verwendung eines Labormörtels verbessern sich die statistischen Kennwerte auf 4,5 und 5,3 Prozent. Mit 8,2 und 9,5 Prozent beziehungsweise 8,6 und 9,5 Prozent werden bei der Restsubstanzbewertung von Wasch- und Unterbetonen die höchsten Werte bestimmt. Das robuste Auswerteverfahren (ohne Eliminierung der Ausreißer) nach dem Entwurf des FGSV-Merkblatts zur statistischen Auswertung von Prüfergebnissen erwies sich in der Form als ungeeignet und bedurfte einer Überarbeitung. Bezüglich der vergleichend mit klassischen und robusten Verfahren gewonnenen Kennwerte ist festzustellen, dass bei sehr homogenen Messergebnissen eines Prüfloses beide Verfahren nahezu die gleichen statistischen Kennwerte liefern. Bei der Eliminierung von Ausreißern sind die Ergebnisse des robusten Verfahrens in der Regel etwas größer als die des klassischen Verfahrens. Die begleitenden vertiefenden Untersuchungen bei der Spaltzugprüfung mit innovativen Prüftechniken lieferten wertvolle Erkenntnisse zur Bewertung der Prüfeinflüsse. N2 - The computational design of concrete pavements according to the requirements of the RDO-Beton 09 requires the splitting tensile strength to be determined according to specifications of the AL Sp-Beton. However, detailed information on the precision of the described test procedure is missing. Therefore, a round robin test was set up in order to determine the statistical parameters of the prescribed splitting tensile strength test on laboratory concrete and cores extracted from concrete pavements in terms of repeatability and reproducibility. 13 testing institutes have been involved in the round robin test to guarantee a representative coverage of the sector. The selected testing institutes have been audited prior the round robin test in order to ensure their capabilities. The round robin test was divided into 8 testing lots for covering the broad field of possible applications. Thereby, the testing lots cover both the initial testing of concrete and quality control of new construction. The latter case implies also the assessment of existing concrete pavements. Additionally, a cementitious mortar was designed in order to consider the influence of the material, such as maximum grain size, on the test procedure. The samples were prepared at BAM to guarantee a uniform sample preparation. Furthermore, a standard operating procedure was prepared to assure constant test conditions at the testing institutes. This standard operating procedure is already partly considered by the corresponding standard. A revision of the data reported by the testing institutes revealed that execution errors, transcription errors as well as typing errors occurred. However, a Lilliefors-Test was conducted to verify the Gaussian distribution of the reported test data and to allow the further statistical analysis. Only view data sets do not follow a Gaussian distribution, has no remarkable influence on the obtained statistical data. By means of the graphical illustration of Mandel’s h- and k-values, abnormalities of the arithmetic mean and variance are depicted. These apparent abnormalities can be identified as outliers using the Grubbs and Cochran test. After eliminating the identified outliers, the corresponding statistical parameters have been determined using the classical method for data analysis. The lowest coefficient of variation that was determined for the splitting tensile strength by using the classical method for assessment of the repeatability and reproducibility of the test procedure amounts to 6.2 and 6.4%, respectively, for the initial testing of concrete. Reducing the material influence by using a cementitious mortar, the corresponding statistical parameters were reduced to 4.5 and 5.3%. On the contrary, the highest statistical values were obtained for the assessment of existing concrete pavements. Here, values of 8.2 and 9.5% were obtained for the exposed aggregate concrete and 8.6 and 9.5% for the subconcrete, respectively. The robust method for data analysis (without elimination of outliers) according to the draft version of the technical bulletin of the FGSV turned out to be inappropriate and required, therefore, a revision. Comparing the statistical parameters obtained by the classical and robust method used for data analysis it can be stated that both methods result in nearly identical values for homogeneous data sets without outliers. Considering outliers in the existing data sets, the statistical parameters obtained by the robust method are slightly higher than the values obtained by the classical method with elimination of outliers. The additional investigations on the splitting tensile strength using innovative test procedures provided valuable findings for the assessment of test results. KW - Verfahrenspräzision KW - Betonfahrbahndecke KW - Prüfverfahren AL Sp-Beton KW - Spaltzugfestigkeit KW - Ringversuch PY - 2022 SN - 978-3-95606-688-7 SN - 0943-9323 VL - Straßenbau Heft S 178 SP - 1 EP - 90 PB - Fachverlag NW in der Carl Ed. Schünemann KG CY - Bremen AN - OPUS4-54957 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Müller, U. A1 - Hüsken, Götz A1 - Gardei, Andre T1 - Begutachtung Berliner Tuffsteinfassaden - Turmruine der Kaiser-Wilhelm-Gedächtniskirche und Charlottenburger Tor N2 - Am Ende des 19. und zu Beginn des 20. Jahrhunderts wurden auch in Berlin vermehrt Bauwerke mit einer Fassadenverblendung aus Eifeler Tuffsteinen errichtet. Die Eifeler Tuffsteine zeichnen sich aufgrund ihrer hohen Porosität einerseits durch eine gute Verarbeitbarkeit aus. Andererseits sind sie nur schwach gebunden und besitzen deshalb eine geringe Verwitterungsbeständigkeit. T2 - Workshop Kulturguterhaltung - Vom Dampfkessel zu Nanomaterialien CY - Berlin, Germany DA - 17.11.2021 KW - Fassade KW - Tuffstein KW - Schalenbildung PY - 2021 SN - 2567-1251 VL - 3 SP - 107 EP - 123 PB - Druckerei G. Bohm CY - Berlin AN - OPUS4-54461 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mundra, Shishir A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten ED - Sena-Cruz, J. ED - Correia, L. ED - Azenha, M. T1 - Electrochemical realkalisation of carbonated "Dalle de Verre" windows N2 - Concrete-glass windows or commonly referred to as “Dalle de Verre” windows are prevalent in historical monuments across Europe. “Dalle de Verre” windows were made by placing cut stained glasses, of various shapes and sizes, into a steel reinforced concrete frame. In addition to the steel reinforcement, a few steel wires run across the concrete elements to hold the glass windows into place. Much of these structures have been damaged due to carbonation of the thin concrete covers and consequent corrosion of the steel reinforcement; and exhibit several cracks due to the expansive nature of corrosion products formed at the steel–concrete interface. This study focussed on understanding the efficacy of electrochemical realkalisation in reinstating the passive state of the steel reinforcement embedded in such concrete glass windows. Simulant “Dalle de Verre” windows (representative of windows at Kaiser-Wilhelm Gedächtniskirche) were produced using different cements with a water/cement ratio of 0.6 and carbonated under accelerated conditions. Post carbonation, the concrete glass windows were electrochemically realkalised using a sacrificial anode. The influence of highly alkaline conditions due to electrochemical realkalisation on the glass-concrete interface has also been investigated. This study shows that the passive state of the steel reinforcement in “Dalle de Verre” windows, particularly at the Kaiser-Wilhelm Gedächtniskirche (memorial church) in Berlin, can be reinstated using the electrochemical realkalisation method. T2 - 3rd RILEM Spring Convention and Conference (RSCC 2020) CY - Online meeting DA - 10.03.2020 KW - Electrochemical realkalisation KW - Carbonation KW - Concrete-glass windows KW - Passivation KW - Dalle-de-verre PY - 2021 SN - 978-3-030-76465-4 U6 - https://doi.org/10.1007/978-3-030-76465-4_15 SN - 2211-0844 VL - RILEM bookseries 34 SP - 163 EP - 171 PB - Springer CY - Cham AN - OPUS4-54299 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Schönsee, Eric A1 - Jeyifous, Olubunni Anthony A1 - Mezhov, Alexander A1 - Hüsken, Götz T1 - Introduction of a monitoring system for Bingham fluids in additive manufacturing with concrete N2 - Freeform additive manufacturing of concrete structures is a rising technology in civil engineering with several fascinating advantages. Nonetheless, to ensure reliability and structural integrity, standards and quality control are required in the future to bring this technology into the market. As the concrete is manufactured continuously, continuous quality control of the printing process is also required, i.e. comprehensive process monitoring. At BAM, a test rig will be installed, enabling the printing of concrete structures with a maximum size of 2 m x 1 m x 1 m (l x w x h). Here, process monitoring is the focus of the test rig. In this study, we show the results of the first pump tests, including the measurement of several parameters such as temperature and pressure along the supply system, i.e. from the concrete pump to the printer head. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Additive manufacturing of concrete KW - Process monitoring KW - Non-destructive testing KW - Bingham fluid PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-556367 SP - 1 EP - 12 AN - OPUS4-55636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kühne, Hans-Carsten A1 - Hüsken, Götz A1 - Mundra, Shishir A1 - Sander, C. A1 - Obermann, S. T1 - Die Betondickglasfenster des Glockenturms am Eiermannbau der Kaiser-Wilhelm-Gedächtniskirche N2 - Die Kaiser-Wilhelm-Gedächtniskirche (KWG) gilt als eine der wichtigsten Sehenswürdigkeiten Berlins in der City West und als ein herausragendes Beispiel für die „Dalle de Verre“ Verglasungen in sakralen Gebäuden. Der vorliegende Beitrag widmet sich der Fassade und den Glasfenstern des neuen Glockenturms, wobei die beschriebenen Szenarien aufgrund der annähernd gleichen Bauweise der restlichen neuen Baukörper in weiten Teilen starke Analogien aufweisen und insofern übertragbar sind. T2 - Workshop Kulturguterhaltung - Vom Dampfkessel zu Nanomaterialien CY - Berlin, Germany DA - 17.11.2021 KW - Kaiser-Wilhelm-Gedächtniskirche KW - Betondickglasfenster KW - Instandsetzung KW - Elektrochemische Realkalisierung PY - 2021 VL - 3 SP - 125 EP - 140 PB - Druckerei G. Bohm CY - Berlin AN - OPUS4-57092 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Larcher, M. A1 - Arrigoni, M. 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 - Design of blast-loaded glazing windows and facades: a review of essential requirements towards standardization N2 - The determination of the blast protection level of laminated glass windows and facades is of crucial importance, and it is normally done by using experimental investigations. In recent years numericalmethods have becomemuch more powerful also with respect to this kind of application. This paper attempts to give a first idea of a possible standardization concerning such numerical simulations. Attention is drawn to the representation of the blast loading and to the proper description of the behaviour of the material of the mentioned products, to the geometrical meshing, and to the modelling of the connections of the glass components to the main structure.The need to validate the numerical models against reliable experimental data, some of which are indicated, is underlined. KW - Standardization KW - Facades KW - Glazing windows KW - Blast-load KW - Design PY - 2016 U6 - https://doi.org/10.1155/2016/2604232 SN - 1687-8094 VL - 2016 SP - Article 2604232, 1 EP - 14 PB - Hindawi Publishing Corporation AN - OPUS4-37124 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Bedon, C. A1 - C., K. A1 - van Doormaal, A. A1 - Haberacker, C. A1 - Hüsken, Götz A1 - Larcher, M. A1 - Saarenheimo, A. A1 - Solomos, G. A1 - Stolz, A. A1 - Thamie, L. A1 - Valsamos, G. T1 - A comparison of existing standards for testing blast resistant glazing and windows N2 - It is important to protect critical buildings (shopping centres, government buildings and embassies), infrastructure and utilities, train and underground stations against being damaged, destroyed or disrupted by deliberate acts of terrorism, criminal activity and malicious behaviour. Normal regulations and building guidelines do not generally take into account these threats. The introduction of appropriate regulations or guidelines, where deemed necessary, should enhance the resilience of buildings and infrastructure against explosion incidents. In order to protect the built infrastructure, methods are required to quantify the resistance of structural components against explosive loading and to assess the hazards resulting from the failure of an element. The applicable state-of-the-art techniques may include either experimental or numerical methods, or a combination of both. Therefore, the thematic group (TG) on the resistance of structures to explosion effects was formed in order to bring the required expertise together, make it commonly available and to find and define harmonised methods and solutions which can be provided to the decision-makers responsible for critical infrastructure protection. This report discusses the differences between the existing standards for testing blast-resistant glazing and windows and it presents basic recommendations for the future development of the suite of European standards in this area. KW - Building industry KW - Accident prevention KW - Glass industry KW - Explosive KW - Industrial infrastructure KW - Risk prevention KW - Urban infrastructure KW - Terrorism KW - Safety standard KW - Technical standard KW - Research report PY - 2014 SN - 978-92-79-46168-2 U6 - https://doi.org/10.2788/361383 SN - 1831-9424 VL - JRC94930 SP - 1 EP - 42 AN - OPUS4-36904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - C., K. A1 - van Doormaal, A. A1 - Haberacker, C. A1 - Hüsken, Götz A1 - Larcher, M. A1 - Saarenheimo, A. A1 - Solomos, G. A1 - Stolz, A. A1 - Thamie, L. A1 - Bedon, C. T1 - Numerical simulations for classification of blast loaded laminated glass: possibilities, limitations and recommendations N2 - It is important to protect critical buildings (shopping centres, government buildings and embassies), infrastructure and utilities, train and underground stations against being damaged, destroyed or disrupted by deliberate acts of terrorism, criminal activity and malicious behaviour. Normal regulations and building guidelines do not generally take into account these threats. The introduction of appropriate regulations or guidelines, where deemed necessary, should, enhance the resilience of buildings and infrastructure against explosion incidents. In order to protect the built infrastructure, methods are required to quantify the resistance of structural components against explosive loading and to assess the hazards resulting from the failure of an element. The applicable state-of-the-art techniques may include either experimental or numerical methods, or a combination of both. Therefore, the thematic group (TG) on the resistance of structures to explosion effects was formed in order to bring the required expertise together, make it commonly available and to find and define harmonised methods and solutions which can be provided to the decision-makers responsible for critical infrastructure protection. The current report summarizes existing best practices for the numerical finite element modelling of blast loading, including the important topics of domain discretisation, implicit/explicit formulation, Lagrangian/Eulerian solvers, the mathematical description of the material behaviour etc. Furthermore recommendations for the modelling of laminated glass elements are formulated and knowledge gaps in this application area are pointed out. Hence the report builds the basis for an actual evaluation of the different numerical methods, their suitability to certain problems, and their capability to support/complement the experimental testing of glass components. It thus provides helpful information to design architects and engineers, and more generally to critical infrastructure stakeholders, responsible for the structural integrity and security of the infrastructure in case of an explosion. KW - building industry KW - explosive KW - accident prevention KW - glass industry KW - industrial infrastructure KW - risk prevention KW - urban infrastructure KW - terrorism KW - technical standard KW - research report PY - 2014 SN - 978-92-79-46172-9 U6 - https://doi.org/doi:10.2788/083832 SN - 1831-9424 SP - 1 EP - 39 AN - OPUS4-36908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Bedon, C. A1 - C., K. A1 - van Doormaal, A. A1 - Haberacker, C. A1 - Hüsken, Götz A1 - Larcher, M. A1 - Millon, O. A1 - Saarenheimo, A. A1 - Solomos, G. A1 - Stolz, A. A1 - Thamie, L. A1 - Valsamos, G. A1 - Williams, A. T1 - A set of essential requirements towards standardising the numerical simulation of blast-loaded windows and facades N2 - The determination of the blast protection level of laminated glass windows and facades is of crucial importance, and it is normally done by using experimental investigations. In recent years numerical methods have become much more powerful also with respect to this kind of application. This report attempts to give a first idea of a possible standardisation concerning such numerical simulations. Attention is drawn to the representation of the blast loading and of the behaviour of the material of the mentioned products, to the geometrical meshing, as well as to the modelling of the connections of the glass components to the main structure. The need to validate the numerical models against reliable experimental data, some of which are indicated, is underlined. KW - building industry KW - accident prevention KW - glass industry KW - explosive KW - industrial infrastructure KW - risk prevention KW - urban infrastructure KW - safety standard KW - technical standard KW - simulation KW - research report PY - 2015 SN - 978-92-79-57507-5 U6 - https://doi.org/doi:10.2788/684747 SN - 1831-9424 SP - 1 EP - 25 AN - OPUS4-36909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Bedon, C. A1 - C., K. A1 - van Doormaal, A. A1 - Haberacker, C. A1 - Hüsken, Götz A1 - Larcher, M. A1 - Millon, O. A1 - Saarenheimo, A. A1 - Solomos, G. A1 - Stolz, A. A1 - Thamie, L. A1 - Valsamos, G. A1 - Williams, A. T1 - Recommendations for the improvement of existing European norms for testing the resistance of windows and glazed facades to explosive effects N2 - It is important to protect critical buildings (shopping centres, government buildings and embassies), infrastructure and utilities, train and underground stations from being damaged, destroyed or disrupted by deliberate acts of terrorism, criminal activity and malicious behaviour. Normal regulations and building guidelines do not generally take into account these threats. The introduction of appropriate regulations or guidelines, where deemed necessary, should enhance the resilience of buildings and infrastructures against explosion incidents. In order to protect the built infrastructure, testing methods are required which can answer the question whether certain building elements can withstand certain loading conditions created by an explosive event. The applicable state-of-the-art techniques may include either experimental or numerical methods, or a combination of both. Therefore, the thematic group (TG) on the resistance of structures to explosion effects was formed in order to bring the required expertise together, to make it commonly available and to find and define harmonised methods and solutions which can be provided to the decision-makers responsible for critical infrastructure protection. The TG described in a fist report JPC87202 the physical phenomena which have to be understood in order to ensure a proper testing of the elements and a correct interpretation of the results. In a second step, the differences between the existing standards for testing blast-resistant glazing and windows have been derived, and a basis for fundamental recommendations for the future development of the suite of European standards has been addressed JRC94930. Based on the prior findings, this report now formulates the proper enhancements of the existing standards in terms of actual recommendations for the improvement of the test standards. KW - building industry KW - accident prevention KW - glass industry KW - explosive KW - industrial infrastructure KW - safety standard KW - technical standard KW - urban infrastructure KW - terrorism KW - research report PY - 2015 SN - 978-92-79-53394-5 U6 - https://doi.org/doi:10.2788/319252 SN - 1831-9424 SP - 1 EP - 42 AN - OPUS4-36910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Babski, Veronika A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Ehlers, Noah A1 - Kühne, Hans-Carsten A1 - Brouwers, H.J.H. ED - Fehling, E. ED - Middendorf, B. ED - Thiemicke, J. T1 - Characterisation of Ultra-High Performance Fibre Reinforced Concrete (UHPFC) under tensile loading by acoustic emission and optical deformation analysis N2 - During the past 20 years, innovative developments in concrete technology have enabled the production of ultra-high performance fibre reinforced concretes (UHPFC) for the protection and preservation of concrete structures. The main characteristics of UHPFC comprise high compressive and flexural strength as well as high ductility compared to normal strength, normal weight concrete (NSC). This paper focuses on the analysis of crack formation and crack propagation in UHPFC under tensile loading under quasistatic conditions by using acoustic emission (AE) and optical deformation analysis (ODA). AE is a non-destructive technique to monitor the development of micro structural damage processes caused by external forces. In this context, AE allows for a continuous monitoring of changes in the microstructure (cracks) over time and the corresponding localisation by appropriate algorithms. The AE measurements were performed along with ODA at the surface of the samples in order to analyse the deformation behaviour of the samples and the crack propagation. For the tests, a UHPFC reference mixture was developed and tested with three different volume percentages of steel fibres (1.0 V.-%, 2.0 V.-%, and 3.0 V.-%). This paper shows that the application of AE is a suitable method to analyse the crack propagation in UHPFC specimens under tensile loading and to localise the crack initiation. Furthermore, insights into the failure mechanism of the fibres are offered by the analysis of the signals of the AE measurements, which allows for a better understanding of UHPFC and its general performance. T2 - 4th International Symposium on Ultra-High Performance Concrete and High Performance Materials (HiPerMat) CY - Kassel, Germany DA - 09.03.2016 KW - UHPFC KW - Tensile loading KW - Acoustic emission KW - Crack formation KW - Optical deformation analysis KW - Crack propagation PY - 2016 SN - 978-3-7376-0094-1 SP - 1 EP - 9 PB - Kassel University Press CY - Kassel AN - OPUS4-36893 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Quercia, G. A1 - Van der Putten, J.J.G. A1 - Hüsken, Götz A1 - Brouwers, H.J.H. T1 - Photovoltaic's silica-rich waste sludge as supplementary cementitious material (SCM) N2 - Waste sludge, a solid recovered from wastewater of photovoltaic-industries, composes of agglomerates of nano-particles like SiO2 and CaCO3. This sludge deflocculates in aqueous solutions into nano-particles smaller than 1 µm. Thus, this sludge constitutes a potentially hazardous waste when it is improperly disposed. Due to its high content of amorphous SiO2, this sludge has a potential use as supplementary cementitious material (SCM) in concrete. In this study the main properties of three different samples of photovoltaic's silica-rich waste sludge (nSS) were physically and chemically characterized. The characterization techniques included: scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), nitrogen physical adsorption isotherm (BET method), density by Helium pycnometry, particle size distribution determined by laser light scattering (LLS) and zeta-potential measurements by dynamic light scattering (DLS). In addition, a dispersability study was performed to design stable slurries to be used as liquid additives for the concrete production on site. The effects on the hydration kinetics of cement pastes by the incorporation of nSS in the designed slurries were determined using an isothermal calorimeter. A compressive strength test of standard mortars with 7% of cement replacement was performed to determine the pozzolanic activity of the waste nano-silica sludge. Finally, the hardened system was fully characterized to determine the phase composition. The results demonstrate that the nSS can be utilized as SCM to replace portion of cement in mortars, thereby decreasing the CO2 footprint and the environmental impact of concrete. KW - Nano-silica sludge (D) KW - Supplementary cementitious materials (D) KW - Pozzolanic index (C) KW - Mortar (E) PY - 2013 U6 - https://doi.org/10.1016/j.cemconres.2013.08.010 SN - 0008-8846 SN - 1873-3948 VL - 54 SP - 161 EP - 179 PB - Pergamon Press CY - New York, NY AN - OPUS4-30384 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Quercia, G. A1 - Spiesz, P. A1 - Hüsken, Götz A1 - Brouwers, H.J.H. T1 - SCC modification by use of amorphous nano-silica N2 - In this study two different types of nano-silica (nS) were applied in self-compacting concrete (SCC), both having similar particle size distributions (PSD), but produced through two different processes: fumed powder silica and precipitated silica in colloidal suspension. The influence of nano-silica on SCC was investigated with respect to the properties of concrete in fresh (workability) and hardened state (mechanical properties and durability). Additionally, the densification of the microstructure of the hardened concrete was verified by SEM and EDS analyses. The obtained results demonstrate that nano-silica efficiently used in SCC can improve its mechanical properties and durability. Considering the reactivity of the two applied nano-silicas, the colloidal type showed a higher reactivity at early age, which influenced the final SCC properties. KW - Nano-silica KW - Self compacting concrete KW - Durability KW - Chloride KW - Freeze-thaw PY - 2014 U6 - https://doi.org/10.1016/j.cemconcomp.2013.09.001 SN - 0958-9465 SN - 1873-393X VL - 45 SP - 69 EP - 81 PB - Elsevier CY - Barking, Essex AN - OPUS4-30385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Viefhues, Eva A1 - Ünal, Murat A1 - Hüsken, Götz A1 - Wellershoff, F. A1 - Mehdianpour, Milad T1 - Zementgebundenes Crashmaterial für Schutzbauteile in explosionsbeanspruchten Fassaden N2 - Die Forderung, für repräsentative Bauwerke wie Botschaften und Flughäfen auch außergewöhnliche Lasten aus Explosion zu berücksichtigen, wurde in jüngerer Vergangenheit zunehmend gestellt. Das aufgrund dieser Lasten zu erwartende Schadensausmaß kann durch den Einsatz von energiedissipierenden Schutzbauteilen in der Fassadenbefestigung begrenzt werden. Die Dissipation der Explosionsenergie in den Schutzbauteilen kann beispielsweise über ein Crashmaterial erfolgen. In diesem Aufsatz werden Untersuchungen an zementgebundenen Materialien, die diesem Zweck dienen sollen, vorgestellt. Der Einfluss unterschiedlicher Zusätze auf die für ein Crashmaterial maßgebenden Eigenschaften wird in einer Parameterstudie untersucht. Als besonders geeignet wird ein Material identifiziert, bei dem die Zugabe eines Gasbildners das Matrixgefüge im Hinblick auf das gewünschte Kraft-Verformungs-Verhalten positiv verändert. Dynamische Versuche mit diesem Material geben Aufschluss über dessen Komprimierungsverhalten bei hohen Stauchraten.----------------------------------------------------------------------------------------------------------------------------------------------- In the past few years public awareness of the need to protect structures against blast effects has risen. Energy dissipating protective components placed at the façade connectors allow protecting people in the building as well as the primary building structure from damage due to blast loads. One possibility to dissipate the blast energy is using protective components with crash material. This paper presents tests on cementitious crash materials studying the effect of different additives to the compression-behavior of the material. Additional experiments enable analyzing the material behavior under static and dynamic test conditions. KW - Explosionsbeanspruchung KW - Energiedissipation KW - Fassadenverankerung KW - Materialkennlinie KW - Crashmaterial KW - Crashkörper KW - Energy dissipation KW - Façade connector KW - Material behavior KW - Crash-material KW - Entwurf und Konstruktion KW - Baustoffe KW - Building materials KW - Conception and design KW - Blast loads PY - 2014 U6 - https://doi.org/10.1002/bate.201400041 SN - 0932-8351 SN - 1437-0999 SN - 0005-6820 SN - 0341-1052 SN - 0932-6359 SN - 0932-8351 VL - 91 IS - 8 SP - 567 EP - 571 PB - Ernst & Sohn CY - Berlin AN - OPUS4-31343 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Frost, Daniel A1 - Hüsken, Götz A1 - Weise, Frank A1 - Berger, J. ED - Domnick, I. ED - Heimann, S. T1 - Analyse von Schädigungsprozessen statischer und dynamischer Spaltzugversuche unter Verwendung innovativer Prüftechnik N2 - Im Rahmen einer Bachelorarbeit und in Kooperation mit der Bundesanstalt für Materialforschung und -prüfung (BAM) wurden die eintretenden Schädigungsprozesse während des Spaltzugversuche mittels innovativer Prüfverfahren untersucht. Ziel war es, in Untersuchungen Erkenntnisse über das Versagensverhalten unter statischer und dynamischer Spaltzugbeanspruchung bei der Variation verschiedener Einflussfaktoren zu gewinnen. Hierfür wurde die Aussagekraft innerer und äußerer Schädigungsindikatoren zur Charakterisierung der auftretenden Bruchmechanismen analysiert. KW - Spaltzugfestigkeit KW - RDO - Beton KW - Innovative Prüftechniken KW - Bruchmechanismus PY - 2014 SN - 978-3-8440-2643-6 SN - 2191-740X N1 - Serientitel: Forum Geo-Bau – Series title: Forum Geo-Bau VL - 4 SP - 89 EP - 96 PB - Shaker AN - OPUS4-31221 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Quercia, G. A1 - Spiesz, P. A1 - Hüsken, Götz A1 - Brouwers, J. ED - Jacobsen, S. ED - Justnes, H. ED - Cepuritis, R. ED - Hornbostel, K. ED - Peng, Y. T1 - Effects of amorphous nano-silica additions on mechanical and durability performance of SCC mixtures N2 - In the recent years the application of nanotechnology in building materials has increased exponentially. One of the most referred and used nano-materials is amorphous silica with particles size in the nano-range, even though its application and effect in concrete has not been fully understood yet. It has been reported that nano-silica (nS) addition increases the compressive strength and reduces the overall permeability of hardened concrete due to the pozzolanic properties which are resulting in finer hydrated phases (C-S-H gel) and densified microstructure (nano-filler and anti leaching effects). These effects enhance the durability of concrete structures such as bridges, quays or off-shore oil facilities in marine environments. In this study two different types of nano-silica were applied in self-compacting concrete (SCC), both having similar particle size distributions (PSD) but produced in two different processes (fumed powder silica and precipitated silica in colloidal suspension). The influence of nanosilica on SCC was investigated with respect to the properties of concrete in the fresh state (workability) and hardened state (mechanical properties and durability). Additionally, the densification of microstructure of the hardened concrete was verified by SEM and EDS analyses. The obtained results demonstrate that an efficient use of nano-silica in SCC can improve its mechanical properties and durability. Considering the reactivity of the two nano-silica studied, colloidal type shown more reactivity at early age, which influenced all the final SCC properties. T2 - ICDC 2012 - International congress on durability of concrete CY - Trondheim, Norway DA - 2012-06-18 KW - Nano-silica KW - Concrete KW - Self Compacting KW - Durability KW - Chloride and Freeze-thaw PY - 2012 SN - 978-82-8208-031-6 SP - A2-4, 1-15 AN - OPUS4-30540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weise, Frank A1 - Hüsken, Götz A1 - Niedack-Nad, Marianne A1 - Wieland, M. T1 - AL Sp-Beton - Präzision des Prüfverfahrens N2 - Für die rechnerische Dimensionierung der Betondecken im Oberbau von Verkehrsflächen für den Neubau sowie die Erneuerung nach RDO-Beton 09 ist die statische Spaltzugfestigkeit an der unteren bzw. unteren und oberen Scheibe des Betonzylinders bzw. Bohrkerns entsprechend der Vorgaben der AL Sp-Beton zu bestimmen. Aufgrund der unzureichenden Kenntnis der Präzision dieses Prüfverfahrens wurden mit einem breit aufgestellten Ringversuch die statistischen Kennwerte an Labor- und Bestandsbetonen unter Vergleich- und Wiederholbedingungen auf der Grundlage des FGSV-Merkblatts über die statistische Auswertung von Prüfergebnissen ermittelt. Für eine möglichst gute statistische Absicherung nahmen an dem Ringversuch dreizehn erfahrene Prüfstellen teil. Zur Abdeckung des vielschichtigen Einsatzes des Prüfverfahrens erfolgte der Ringversuch an acht Prüflosen. Dabei berücksichtigen einerseits die Prüflose 1 und 2 mit den im Transportbetonwerk hergestellten Betonzylindern die Erst-/Eignungsprüfung und das darauf aufbauende Prüflos 3 mit Bohrkernen aus einer im Feldversuch hergestellten Fahrbahnplatte mit gleicher Betonrezeptur die Übereinstimmungskontrolle bei Neubaumaßnahmen. Andererseits findet der Einsatz des Prüfverfahrens bei der Restsubstanzbewertung von Betonfahrbahnplatten bei den Prüflosen 4 bis 7 mit den Bohrkernen aus vier in Waschbetonbauweise ausgeführten Fahrbahnplatten Berücksichtigung. Das zusätzlich aufgenommene Prüflos 8 mit einem Labormörtel dient der Herausarbeitung des Materialeinflusses auf die Präzision der Spaltzugfestigkeitsprüfung. Zusammenfassend kann festgestellt werden, dass die Präzision der in der AL SP-Beton beschriebenen Spaltzugfestigkeitsprüfung mit einem Variationskoeffizienten von weniger als 10 % unter Wiederhol- und Vergleichsbedingungen hinreichend genau ist. Der geringe Unterschied zwischen den Variationskoeffizienten unter Wiederhol- und Vergleichsbedingungen lässt zusätzlich den Schluss zu, dass der Einfluss des unterschiedlichen Personals und der verschiedenartigen Prüftechniken bei den einzelnen Prüfstellen relativ gering ist. Die im Rahmen des Ringversuchs gewonnenen Erkenntnisse haben bereits partiell Eingang in die Normung gefunden. KW - Betonfahrbahndecken KW - Spaltzugfestigkeit KW - Ringversuch KW - Verfahrenspräzision PY - 2014 SN - 0039-2162 VL - 66 IS - 10 SP - 790 EP - 798 PB - Kirschbaum-Verl. CY - Bonn-Bad Godesberg AN - OPUS4-32066 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Hüsken, Götz A1 - Niedack-Nad, Marianne A1 - Wieland, M. T1 - AL Sp-Beton - Präzision des Prüfverfahrens N2 - Für die rechnerische Dimensionierung der Betondecken im Oberbau von Verkehrsflächen für den Neubau sowie die Erneuerung nach RDO Beton 09 ist die statische Spaltzugfestigkeit an der unteren bzw. unteren und oberen Scheibe des Betonzylinders bzw. Bohrkerns entsprechend der Vorgaben der AL Sp-Beton zu bestimmen. Aufgrund der unzureichenden Kenntnis der Präzision dieses Prüfverfahrens wurden mit einem breit aufgestellten Ringversuch die statistischen Kennwerte an Labor- und Bestandsbetonen unter Vergleich- und Wiederholbedingungen auf der Grundlage des „Merkblatts über die statistische Auswertung von Prüfergebnissen" ermittelt. Für eine möglichst gute statistische Absicherung nahmen an dem Ringversuch 13 erfahrene Prüfstellen teil. Zur Abdeckung des vielschichtigen Einsatzes des Prüfverfahrens erfolgte der Ringversuch an acht Prüflosen. Dabei berücksichtigen einerseits die Prüf lose 1 und 2 mit den im Transportbetonwerk hergestellten Betonzylindern die Erst-/Eignungsprüfung und das darauf aufbauende Prüflos 3 mit Bohrkernen aus einer im Feldversuch hergestellten Fahrbahnplatte mit gleicher Betonrezeptur die Übereinstimmungskontrolle bei Neubaumaßnahmen. Andererseits findet der Einsatz des Prüfverfahrens bei der Restsubstanzbewertung von Betonfahrbahnplatten bei den Prüflosen 4 bis 7 mit den Bohrkernen aus vier in Waschbetonbauweise ausgeführten Fahrbahnplatten Berücksichtigung. Das zusätzlich aufgenommene Prüflos 8 mit einem Labormörtel dient der Herausarbeitung des Materialeinflusses auf die Präzision der Spaltzugfestigkeitsprüfung. Zusammenfassend kann festgestellt werden, dass die Präzision der in der AL SP-Beton beschriebenen Spaltzugfestigkeitsprüfung mit einem Variationskoeffizienten von weniger als 10 % unter Wiederhol- und Vergleichbedingungen hinreichend genau ist. Der geringe Unterschied zwischen den Variationskoeffizienten unter Wiederhol- und Vergleichbedingungen lässt zusätzlich den Schluss zu, dass der Einfluss des unterschiedlichen Personals und der verschiedenartigen Prüftechniken bei den einzelnen Prüfstellen relativ gering ist. Die im Rahmen des Ringversuchs gewonnenen Erkenntnisse haben bereits partiell Eingang in die Normung gefunden. T2 - Betonstraßentagung 2013 CY - Karlsruhe, Germany DA - 19.09.2013 KW - Spaltzugfestigkeit KW - Ringversuch KW - Präzision KW - Vergleich- und Wiederholbedingungen PY - 2013 SN - 978-3-86446-076-0 N1 - Serientitel: FGSV-Schriftenreihe der Arbeitsgruppe Betonbauweisen – Series title: FGSV-Schriftenreihe der Arbeitsgruppe Betonbauweisen SP - 106 EP - 122 AN - OPUS4-30622 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Meinel, Dietmar A1 - Babski, Veronika A1 - Kühne, Hans-Carsten T1 - Methoden zur Analyse des Bruchverhaltens hochfester Stahlfaserbetone N2 - Hochfeste und ultrahochfeste Stahlfaserbetone eignen sich aufgrund ihrer Eigenschaften für den Einsatz bei extremen mechanischen Beanspruchungen. Das für diesen Einsatz erforderliche duktile Bruchverhalten unter Zugbeanspruchung wird ausschließlich durch die Zugabe von geeigneten Stahlfasern und deren Wirkung in der Zementsteinmatrix erreicht. Für eine gezielte stoffliche Optimierung des Systems sind fundierte Kenntnisse zur Wirkungsweise der Stahlfasern notwendig, die bei bisherigen Untersuchungen lediglich auf Basis von klassischen Messverfahren zerstörender Prüfungen gewonnen wurden. Durch das Einbeziehen von Methoden der zerstörungsfreien Materialcharakterisierung können das Bruchverhalten hochfester und ultrahochfester Stahlfaserbetone orts- und zeitaufgelöst untersucht und die einzelnen Phasen des Schädigungsprozesses identifiziert werden. Anhand der vorliegenden Ergebnisse von Zugversuchen eines ultrahochfesten Stahlfaserbetons wird der kombinierte Einsatz von Methoden der zerstörungsfreien Materialprüfung gezeigt und deren Anwendbarkeit in der Analyse des Bruchverhaltens diskutiert. Das Hauptaugenmerk liegt dabei auf der Charakterisierung der ausschlaggebenden Versagensmodi unter Zugbelastung durch die einzelnen Verfahren und dem Vergleich zu klassischen Messmethoden (z. B. Extensometer). Die Zugversuche wurden dazu parallel durch optische Verformungsanalyse mittels Bildkorrelation (DIC), Schallemissionsanalyse (SEA) und 3-D-Computertomografie (CT) begleitet. KW - Stahlfaserbeton KW - Zugbeanspruchung KW - Optische Verformungsanalyse KW - Schallemission KW - Computertomografie PY - 2016 U6 - https://doi.org/10.1002/bate.201600056 SN - 1437-0999 VL - 93 IS - 10 SP - 711 EP - 716 PB - Ernst & Sohn CY - Berlin AN - OPUS4-37767 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Pirskawetz, Stephan T1 - Bewertung und Lebensdauerprognose von Brückenbauwerken – Grundlagenuntersuchungen zur Zustandsüberwachung mittels zerstörungsfreier Prüftechniken N2 - Anhand der aus Biegeversuchen vorliegenden Ergebnisse wird der Einsatz unterschiedlicher Methoden der zerstörungsfreien Materialprüfung gezeigt und deren Anwendbarkeit für die Analyse des Verformungsverhaltens von Stahlbetonbalken diskutiert. Hierzu wurde das Verformungsverhalten eines Stahlbetonbalken (L = 2,75 m) in einem 4-Punkt-Biegeversuch untersucht. Das Hauptaugenmerk liegt dabei auf der Charakterisierung der ausschlaggebenden Versagensmodi durch die einzelnen zerstörungsfreien Prüfverfahren und der Vergleich zu klassischen Messmethoden (z.B. Verformungsmessung mittels induktiver Wegaufnehmer). Die Biegeversuche wurden dazu durch Schallemissionsanalyse (SEA) und optische Verformungsanalyse mittels Bildkorrelation (DIC) begleitet. T2 - Fachtagung „Prüfen von Beton“ des InformationsZentrum Beton GmbH CY - Berlin, Germany DA - 06.10.2016 KW - Stahlbeton KW - Tragverhalten bei Biegebeanspruchung KW - Rissbildung KW - Schallemission KW - Optische Verformungsanalyse PY - 2016 AN - OPUS4-37820 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ünal, Murat A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten ED - Ludwig, H.-M. T1 - Entwicklung eines PCC-Leichtmörtels zur Instandsetzung einer denkmalgeschützten Sichtbetonfassade N2 - Der Schutz und Erhalt der Originalsubstanz stehen im Mittelpunkt jeglicher denkmalpflegerischer Instandhaltungsmaßnahmen. Das äußere Erscheinungsbild spielt hierbei - im Gegensatz zur klassischen Betoninstandsetzung - eine größere Rolle. Nichtsdestotrotz dürfen die technischen Belange auch hier nicht außer Acht gelassen werden. Die Ermittlung des Ist- und Sollzustands stellt die Grundlage einer dauerhaften Instandsetzung dar. Der vorliegende Beitrag zeigt Schäden und Schadensursachen an einem denkmalgeschützten Gebäude in Leichtbetonbauweise auf. Das Bauwerk wurde hinsichtlich seines Schädigungsgrads, -umfangs und der maßgeblichen Schadensursachen untersucht. Im Rahmen dieser Untersuchungen wurden gehäuft Risse, Abplatzungen und Bewehrungskorrosion festgestellt. Die durch eine Brettschalung strukturierte Sichtbetonfassade soll im Zuge der Instandsetzungsmaßnahme möglichst originalgetreu wiederhergestellt werden. Bei der Auswahl von geeigneten Instandsetzungsmethoden und -produkten konnte aufgrund fehlender Normen und Richtlinien für die Instandsetzung von denkmalgeschützten Leichtbetonbauten nicht auf bereits existierende Produkte und Methoden zurückgegriffen werden. Daher wurde in Anlehnung an die Richtlinie "Schutz und Instandsetzung von Betonbauteilen" (RL SIB) des DAfStB eine polymermodifizierte Betonergänzungsmasse mit leichter Gesteinskörnung entwickelt. Ausgehend von der Hauptschadensursache, der karbonatisierungsinduzierten Bewehrungskorrosion, wurden erforderliche Eigenschaften der Betonergänzungsmasse in enger Absprache mit der zuständigen Denkmalschutzbehörde und dem involvierten Fachplaner abgestimmt. Neben den grundlegenden mechanischen Eigenschaften spielen in diesem Anwendungsfall spezielle Eigenschaften wie z.B. farbliehe Anpassung der Betonergänzungsmasse, Möglichkeit der Oberflächenstrukturierung, Zeitfenster der Verarbeitbarkeit sowie die Modellierbarkeit eine wichtige Rolle. Der entwickelte PCC-Leichtmörtel berücksichtigt dabei auch den Einfluss einer geringen Schwind- und Quellneigung der Betonergänzungsmasse um Delaminierung infolge unterschiedlicher Längenänderungen zu vermeiden und somit eine dauerhafte Instandsetzung zu gewährleisten. Weiterhin wurde das Verbundverhalten des entwickelten PCCL Leichtmörtels für unterschiedliche Schichtaufbauten untersucht. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Concrete-glazing KW - Dalles de verres KW - Cathodic corrosion protection KW - Heritage KW - Restoration KW - Maintenance PY - 2015 SN - 978-3-00-050225-5 VL - 2 SP - 30-04, 2-125 - 2-132 AN - OPUS4-34876 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Van Doormaal, A. A1 - Haberacker, C. A1 - Hüsken, Götz A1 - Larcher, M. A1 - Saarenheimo, A. A1 - Solomos, G. A1 - Stolz, A. A1 - Thamie, L. A1 - Valsamos, G. T1 - Review report of testing methods - ERNCIP thematic area resistance of structures to explosion effects - Deliverable D1 N2 - It is important to protect critical buildings (shopping centres, government buildings and embassies), infrastructure and utilities, train and underground stations against being damaged, destroyed or disrupted by deliberate acts of terrorism, criminal activity and malicious behaviour. Normal regulations and building guidelines do not generally take into account these threats. The introduction of regulations or guidelines should support the resilience of the buildings and infrastructure against explosive incidents. In order to protect the infrastructure, methods are required to quantify the resistance of structural elements against explosive loading and to assess the hazards resulting from failure of an element. The applicable state-of-the-art techniques may be either experimental or numerical methods, or a combination of both. Therefore, the thematic group (TG) on the resistance of structures to explosion effects was formed in order to bring the required expertise together, make it commonly available and to find and define harmonised methods and solutions which can be provided to the decision-makers responsible for critical infrastructure protection. This first report of the TG gives a comprehensive summary of the existing methods which can be used to analyse and test the resistance of glazing and windows under blast-loading conditions. Within this context, the experimental methods of testing using high explosives and testing using blast simulators called shock tubes is presented and explained. In addition, the potential of numerical simulations is highlighted in terms of their applicability to the different glass materials. A short, comprehensive theoretical background is given for each method. Based on this, each method is described with its requirements, realisation and the related measurement techniques. Furthermore, an interpretation of the measurements is highlighted. For the numerical simulations, the basic discretisation and calculations schemes are presented in combination with the available constitutive material descriptions for the different significant materials. Finally the chances for verification and validation of the numerical results are presented. Hence the report builds the basis for an actual evaluation of the different test methods and their applicability to certain problems, and provides helpful information for critical infrastructure stakeholders, owners and operators considering the structural resistance of the infrastructure to the effects of explosion in a comprehensive document. KW - Critical infrastructure KW - Explosion effects KW - Shock tube KW - Arena test KW - Simulation KW - Building industry KW - Accident prevention KW - Explosive KW - Industrial infrastructure KW - Risk prevention KW - Urban infrastructure KW - Terrorism KW - Technical standard KW - Research report PY - 2013 SN - 978-92-79-35104-4 U6 - https://doi.org/10.2788/57271 SN - 1831-9424 SP - JRC87202, 1 EP - 74 AN - OPUS4-33038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ünal, Murat A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten T1 - Development of a polymer-modified lightweight mortar for the repair of exposed concrete facades on historic buildings N2 - Reinforced concrete buildings are frequently damaged by cracks, spalling and corroded reinforcement bars. The present article focuses on the damage analysis of one of the first buildings in Berlin that was constructed using reinforced lightweight concrete, which makes it historically important. The compressive strength, carbonation depth, location and diameter of reinforcement bars as well as moisture and salt profiles were determined. The carbonationinduced corrosion of the reinforcement bars represented the main damage of the building. Certified repair mortars with lightweight aggregates (LWA) do not exist on the German market. Therefore, an appropriate repair mortar was developed in accordance with DIN EN 1504 and the German guideline for the repair and protection of concrete structures (RL-SIB). On the one hand, historic preservation requirements, such as: colour of the mortar, possibilities of surface patterning, maximum preservation of the original substance and reversibility of any Intervention must be met. On the other hand, technical requirements of the relevant Standards must be achieved. The developed mix was designed to resist the identified causes of deterioration. Thermal strains within the repair mortar and between the repair mortar and the Substrate influence the crack formation and thus the durability. Therefore, special attention was paid to the bonding and shrinking behaviour of the concrete repair System. By using polymers, both hardened mortar properties and durability were influenced positively. T2 - XVII. ERMCO congress CY - Istanbul, Turkey DA - 2015-06-04 KW - Lightweight concrete KW - Repair mortar KW - Historic building KW - Architectural use KW - Polymers KW - Shrinkage PY - 2015 SN - 978-605-84253-0-9 SP - 306 EP - 314 AN - OPUS4-33607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kühne, Hans-Carsten A1 - Hüsken, Götz T1 - МЕТОДЫ ИСПЫТАНИЯ БЕТОНА НА ЗАМОРАЖИВАНИЕ-ОТТАИВАНИЕ И СТРОИТЕЛЬНЫХ РАСТВОРОВ – НА СКЛОННОСТЬ К РАССЛОЕНИЮ N2 - До 1970-х годов производители бетона и ЖБИ определяли свой продукт исключительно как долговечный строительный материал. В последующие годы инженеры-строители ввели такие термины как устойчивость и экспозиция. Современные бетонные технологии учитывают, что определенные строительные материалы (в частности, бетоны) обладают высокой устойчивостью к замораживанию-оттаиванию и расслоению. T2 - International Concrete Conference & Exhibition CY - St. Petersburg, Russia DA - 06.12.2016 KW - бетон KW - зaморозок KW - метод испытания PY - 2016 AN - OPUS4-38661 LA - rus AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pahlavan, L. A1 - Pirskawetz, Stephan A1 - Hüsken, Götz A1 - Blacquière, G. T1 - Sensitivity of ultrasonic waves to surface-breaking cracks in reinforced concrete beams N2 - The interaction mechanism of ultrasonic waves with surface-breaking cracks in reinforced concrete has been studied. For this, a detailed numerical analysis of the medium was first conducted using the spectral finite element method. Subsequently, measurements were conducted on a reinforced beam sample before and after mechanical-load-induced cracking. It was concluded that for the considered configuration, waves passing through the cracks dominated the tip-diffracted ones. In addition, substantial changes in the travel time and amplitude of the signals were observed when cracks were present. T2 - 8th International Conference on Acoustic Emission - IIIAE 2016 CY - Kyoto, Japan DA - 5 December 2016 KW - Ultrasonic waves KW - Reinforced concrete beam KW - Cracks PY - 2016 SP - 237 EP - 242 AN - OPUS4-38913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hu, Nanjie A1 - Hüsken, Götz A1 - Gluth, Gregor A1 - Kühne, Hans-Carsten T1 - The influence of activator composition on the strength, shrinkage and chloride migration resistance of alkali-activated slag mortars N2 - Alkali-activated slag materials are known for their high Chloride penetration resistance. This makes them potentially applicable as repair systems for damaged steel-reinforced concrete structures, which are exposed to chloride attack. For this purpose, the influence of the activator composition, i.e. the SiO2 and Na2O concentration of the alkaline solution on a) the compressive strength, b) shrinkage and mass change and c) the resistance against chloride penetration of four alkali-activated slag mortars (AASM) were studied. An ordinary Portland cement-based mortar was used as the reference sample. Increasing SiO2 and Na2O concentrations increased the strength, shrinkage and mass loss of the AASMs. The resistance of the mortars against chloride penetration was evaluated using the non-steady-state migration coefficient Dnssm obtained from NT BUILD 492. The results indicate that the Dnssm is related to differences in the pore solution of the AASMs rather than to differences in their microstructure. An upcoming study of the authors is going to evaluate this hypothesis by the accelerated chloride penetration (diffusion) test. T2 - 6th International Conference Non-Traditional Cement and Concrete 2017 CY - Brno, Czech Republic DA - 19.06.2017 KW - Alkali-activated slag mortar KW - Strength KW - Shrinkage KW - Chloride migration coefficient PY - 2018 U6 - https://doi.org/10.4028/www.scientific.net/KEM.761.61 SN - 1662-9795 VL - 761 SP - 61 EP - 64 PB - Trans Tech Publications CY - Switzerland AN - OPUS4-43884 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shamsuddoha,, Md A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten A1 - Thiele, Marc T1 - Remediation of Cracks Formed in Grouted Connections of Offshore Energy Structures under Static Loads N2 - The future energy demand necessitates the exploration of all potential energy sources both onshore and offshore. Global trend has shifted towards offshore energy, which can be obtained from either carbon intensive or renewable options, hence requiring structures such as rigs, platforms, and monopiles. Most of these structures adopt easily installable construction techniques, where lower foundation need to be connected with the super structure by mean of grouted composite joints. Generally, these composite connections have exterior sleeve, interior pile and infill grout. Being located in remote offshore conditions, connections can experience considerable adverse loading during their lifetimes. Degradations were reported inside similar connections, which were installed in last three decades. Besides, grouting in the offshore sites may often be proven difficult, which eventually leads to reduced capacity of connections in the long run. Thus, repair and rehabilitation of such connections should be planned ahead to minimize operational delays and costs in the future. This study aims at characterizing the nature of crack generation in grouted connections and thereby identifying the potential of repair using suitable repair material. Scaled grouted joints were manufactured using a novel mold, and connections were loaded under static load to visualize the main failure pattern. The failure mechanism and loading capacity are found compatible to previous results from earlier literature. Grouted connection was then repaired using cementitious injectable grout. The effectiveness of the repair system is also discussed. T2 - Twenty-eighth (2018) International Ocean and Polar Engineering Conference CY - Sapporo, Japan DA - 10.06.2018 KW - Offshore KW - Energy KW - Grouted Connection KW - Cracks KW - Repair KW - Rehabilitation PY - 2018 SP - 120 EP - 126 AN - OPUS4-45227 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hu, Nanjie Hu A1 - Hüsken, Götz A1 - Gluth, Gregor A1 - Kühne, Hans-Carsten T1 - Influence of activator composition on the strength, shrinkage and chloride migration resistance of alkali-activated slag mortars N2 - Alkali-activated slag materials are known for their high Chloride penetration resistance. This makes them potentially applicable as repair systems for damaged steel-reinforced concrete structures, which are exposed to chloride attack. For this purpose, the influence of the activator composition, i.e. the SiO2 and Na2O concentration of the alkaline solution on a) the compressive strength, b) shrinkage and mass change and c) the resistance against chloride penetration of four alkali-activated slag mortars (AASM) were studied. An ordinary Portland cement-based mortar was used as the reference sample. Increasing SiO2 and Na2O concentrations increased the strength, shrinkage and mass loss of the AASMs. The resistance of the mortars against chloride penetration was evaluated using the non-steady-state migration coefficient Dnssm obtained from NT BUILD 492. The results indicate that the Dnssm is related to differences in the pore solution of the AASMs rather than to differences in their microstructure. An upcoming study of the authors is going to evaluate this hypothesis by the accelerated chloride penetration (diffusion) test. T2 - The 6th International Conference on Non-Traditional Cement and Concrete CY - Brno, Czech Republic DA - 20.06.2017 KW - Alkali-activated slag mortar KW - Strength KW - Shrinkage KW - Chloride migration coefficient PY - 2017 AN - OPUS4-44080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Wagner, L.-C. A1 - Gluth, Gregor A1 - Pirskawetz, Stephan A1 - Kühne, Hans-Carsten T1 - Application of Steel Fibres in Alkali-Activated Mortars N2 - Alkali-activated materials are ideal for the repair of concrete structures in harsh environmental conditions due to their high durability in chemically aggressive environments. However, slag-based mortars, in particular, are prone to shrinkage and associated cracks. In this respect, the application of steel fibres is one solution to reduce the formation of shrinkage induced cracks and to improve post cracking behaviour of these mortars. This study investigated the influence of two different types of steel fibres on the tensile properties of two alkali-activated mortars. Direct tensile tests and single fibre pull-outs were performed to analyse the determining failure modes both on macro and micro scale. Mechanical testing was accompanied by non-destructive testing methods such as digital image correlation and acoustic emission for a detailed analysis of the fracture process. T2 - Local Mechanical Properties - LMP 2019 CY - Prague, Czech Republic DA - 06.11.2019 KW - Alkali-activated materials KW - Fibre pull-out KW - Steel fibres KW - Tensile strength PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-509291 UR - https://ojs.cvut.cz/ojs/index.php/APP/article/view/6695 VL - 27 SP - 90 EP - 95 CY - Prague, Czech Republic AN - OPUS4-50929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ünal, Murat A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten T1 - Betonkorrosion und Betoninstandsetzung vor dem Hintergrund der DIN EN 1504 T2 - Bauen im Bestand CY - Northeim DA - 2014-11-20 PY - 2014 AN - OPUS4-32423 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Ünal, Murat A1 - Kühne, Hans-Carsten T1 - Betonkorrosion und Betoninstandsetzung vor dem Hintergrund der DIN EN 1504 T2 - Bauen im Bestand CY - Rendsburg DA - 2014-11-06 PY - 2014 AN - OPUS4-32424 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Quercia, G. A1 - Hüsken, Götz A1 - Brouwers, H.J.H. T1 - Effect of olivine nano-silica additions on the fresh and hardened behaviour of cement pastes and mortars N2 - The high demand for sustainable and durable building materials requires profound knowledge on the material properties. In this respect, the phenomena occurring at nano-level are of crucial importance for the design of new building materials. Therefore, all around the world, increasing amounts of funding are being directed to research projects dealing with material properties on nano-level, which is claimed to have tremendous potential for the future. One of the most referred to and used cementitious nano-material is amorphous silica with a particle size in the nano-range, even though its application and effects on concrete have not been fully understood yet. Olivine (Mg,Fe)2Si04 is the fastest weathering siiicate mineral dissolving easily in acid. Düring dissolution in acid the metallic ions (Mg2+,Fe2+) are replaced by H+, yielding Si(OH)4 monomers and metallic ions in solution. After cleaning treatments an amorphous nano-silica is obtained. The produced olivine nano-silica (OnS) has a specific surface area between 100 and 400 m2/g, the size of the primary particles, which are agglomerated in Clusters, ranges from 10 to 25 nm and the impurity content is below 5 % IV. Literature related with the application of OnS in cement based materials is scarce; only one research work performed by Justnes and Ostnor 121 is available. Thus, the effect of adding OnS in cement based Systems has been not studied. Based on this, the present research aims on elucidating the effects of OnS in the fresh and hardened state of cement pastes and mortars. T2 - 1st International conference on the chemistry of construction materials CY - Berlin, Germany DA - 07.10.2013 KW - Nano-silica KW - Self compacting concrete KW - Durability KW - Chloride KW - Freeze-thaw PY - 2013 SN - 978-3-936028-75-1 SP - 179 EP - 182 AN - OPUS4-30410 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Wagner, L.-C. A1 - Gluth, Gregor A1 - Pirskawetz, Stephan A1 - Kühne, Hans-Carsten T1 - Application of Steel Fibres in Alkali-Activated Mortars N2 - Alkali-activated materials are ideal for the repair of concrete structures in harsh environmental conditions due to their high durability in chemically aggressive environments. However, slag-based mortars, in particular, are prone to shrinkage and associated cracks. In this respect, the application of steel fibres is one solution to reduce the formation of shrinkage induced cracks and to improve post cracking behaviour of these mortars. This study investigated the influence of two different types of steel fibres on the tensile properties of two alkali-activated mortars. Direct tensile tests and single fibre pull-outs were performed to analyse the determining failure modes both on macro and micro scale. Mechanical testing was accompanied by non-destructive testing methods such as digital image correlation and acoustic emission for a detailed analysis of the fracture process. T2 - 14th International Conference on Local Mechanical Properties CY - Prague, Czech Republic DA - 06.11.2019 KW - Steel fibres KW - Alkali-activated materials KW - Tensile strength KW - Fibre pull-out PY - 2019 AN - OPUS4-49578 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shamsuddoha, Md A1 - Hüsken, Götz A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Baeßler, Matthias T1 - Long-term mechanical and shrinkage properties of cementitious grouts for structural repair N2 - Grouts have numerous applications in construction industry such as joint sealing, structural repair, and connections in precast elements. They are particularly favoured in rehabilitation of structures due to penetrability and convenience of application. Grouts for repair applications typically require high-performance properties such as rapid strength development and superior shrinkage characteristics. Sometimes industrial by-products referred as supplementary cementitious materials (SCM) are used with neat cement due to their capabilities to provide binding properties at delayed stage. Micro silica, fly ash and metakaolin are such SCMs, those can modify and improve properties of cement products. This study aims at investigating long-term mass loss and linear shrinkage along with long-term compressive and flexural strength for grouts produced from ultrafine cement and SCMs. A series of mixtures were formulated to observe the effect of SCMs on these grout properties. Properties were determined after 365 days of curing at 23oC and 55% relative humidity. The effect of SCMs on the properties are characterised by statistical models. Response surfaces were constructed to quantify these properties in relation to SCMs replacement. The results suggested that shrinkage was reduced by metakaolin, while micro silica and fly ash had positive effects on compressive and flexural strength, respectively. T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) CY - Rovinj, Croatia DA - 20.03.2019 KW - Grout KW - Long-term shrinkage KW - Micro silica KW - Fly ash KW - Metakaolin PY - 2019 U6 - https://doi.org/10.21809/rilemtechlett.2019.82 SN - 2518-0231 VL - 4 SP - 9 EP - 15 PB - RILEM Publications SARL CY - 4 avenue du Recteur Poincaré, 75016 Paris, France AN - OPUS4-48712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Shamsuddoha, Md A1 - Thiele, Marc A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten T1 - Comparison of cracks formed in scaled grouted connection of offshore energy structures under static and cyclic loads N2 - Global energy consumption will increase in the future necessitating both fossil fuels and renewable energy choices - especially wind energy. Such high energy demand requires installation of offshore energy structures, rigs, platforms and towers, which are susceptible to adverse environmental conditions along with maintenances. Due to their large size and remote locations, cylindrical grouted joints are often adopted between substructure and foundation in these offshore platforms and wind structures such as monopiles. However, these connections are composite structures with exterior sleeve, interior pile and infill mortar. Degradation and settlements were reported inside similar connections, which were installed in last three decades. Besides, grouting in the offshore sites were proven difficult to obtain ideal load bearing capacity. In-situ loading conditions were also found to be affecting the failure mechanism inside such connections. This study aims at characterizing the nature of cracks generated in these grouted connections under both static and cyclic loading. Scaled grouted joints were manufactured using a novel reusable mold, and connections were loaded to failure to visualize the main failure patterns. An assessment between failure under these two types of load is drawn along with comparison to previously available literature. T2 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures CY - Potsdam, Germany DA - 27.08.2019 KW - Grouted connection KW - Crack formation KW - Crack pattern KW - Static load KW - Cyclic load PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-487961 SP - Th.2.A.1-1 EP - Th.2.A.1-9 AN - OPUS4-48796 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Shamsuddoha, Md A1 - Thiele, Marc A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten T1 - Comparison of cracks formed in scaled grouted connection of offshore energy structures under static and cyclic loads N2 - Global energy consumption will increase in the future necessitating both fossil fuels and renewable energy choices - especially wind energy. Such high energy demand requires installation of offshore energy structures, rigs, platforms and towers, which are susceptible to adverse environmental conditions along with maintenances. Due to their large size and remote locations, cylindrical grouted joints are often adopted between substructure and foundation in these offshore platforms and wind structures such as monopiles. However, these connections are composite structures with exterior sleeve, interior pile and infill mortar. Degradation and settlements were reported inside similar connections, which were installed in last three decades. Besides, grouting in the offshore sites were proven difficult to obtain ideal load bearing capacity. In-situ loading conditions were also found to be affecting the failure mechanism inside such connections. This study aims at characterizing the nature of cracks generated in these grouted connections under both static and cyclic loading. Scaled grouted joints were manufactured using a novel reusable mold, and connections were loaded to failure to visualize the main failure patterns. An assessment between failure under these two types of load is drawn along with comparison to previously available literature. T2 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures CY - Potsdam, Germany DA - 27.08.2019 KW - Grouted connection KW - Crack formation KW - Crack pattern KW - Static load KW - Cyclic load PY - 2019 AN - OPUS4-48797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geißler, Peter A1 - Schwarz, Johannes A1 - Cuéllar, Pablo A1 - Hüsken, Götz A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten A1 - Morrone, C. T1 - Compaction grouting to improve the pile bearing capacity in non-cohesive soil N2 - The aim of an ongoing research project is to develop a design approach for typical offshore driven piles (e.g. Jacket piles) based on the application of injections by compaction grouting directly at the pile shaft. The paper aims to present the results of laboratory and in-situ tests, which reveal the efficiency and the promising potential of the optimised foundation concept for a more economic dimensioning of pile foundations and to increase their bearing capacity in non-cohesive soil at any moment after installation. T2 - Twenty-ninth International Ocean and Polar Engineering Conference CY - Honolulu, HI, USA DA - 16.06.2019 KW - Offshore Pile Foundation KW - Compaction Grouting KW - Grout KW - Injection Sequence KW - Tensile Capacity PY - 2019 SN - 978-1-880653-85-2 SN - 1098-6189 VL - II SP - 2178 EP - 2184 PB - International Society of Offshore and Polar Engineers (ISOPE) CY - Cupertino, California, USA AN - OPUS4-48505 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hüsken, Götz A1 - Shamsuddoha, Md A1 - Pirskawetz, Stephan A1 - Hofmann, Detlef A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten T1 - Potential of a Repair System for Grouted Connections in Offshore Structures: Development and Experimental Verification N2 - Grouted connections are intensively used in offshore rigs, platforms as well as jacket and monopile offshore wind turbine structures. Being located in remote offshore conditions, these connections can experience considerable adverse loading during their lifetimes. Degradation was reported inside similar connections, which were installed in the last three decades. Grouting in the offshore sites may often be proven difficult, which eventually leads to reduced load-bearing capacity of connections in the long run. Thus, repair and rehabilitation of such connections should be planned ahead to minimize operational delays and costs. In this study, scaled grouted connections were manufactured using a novel mould, whose integrity were monitored using digital image correlation (DIC). The connections were loaded under static load to visualize the main failure pattern using distributed fibre optic sensors and acoustic emission (AE) analysis. Grouted connections were then repaired using a cementitious injectable grout. The effectiveness of the grout injection was monitored using dye penetration technique. Finally, specimens are reloaded to identify the potential of such repair for grouted connections. KW - Offshore KW - Grouted connection KW - Fibre optic sensors KW - Acoustic emission analysis KW - Cracks KW - Repair KW - Rehabilitation KW - Static loading PY - 2021 U6 - https://doi.org/10.1016/j.marstruc.2021.102934 VL - 77 SP - 102934 PB - Elsevier Ltd. AN - OPUS4-52059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Gründer, Klaus-Peter A1 - Kadoke, Daniel T1 - The load-bearing behaviour of a reinforced concrete beam investigated by optical measuring techniques N2 - Bending beams and slabs are typical examples for structural elements used for reinforced concrete structures such as bridge girders, T-beams and bridge decks. Their strength related failure modes at maximum loading can be divided into bending and shear failure. The failure of beams loaded in bending can occur with or without indication. Therefore, conventional design concepts aim on failure modes with sufficient indication (e.g. large deflections or cracks), as it occurs in the case of secondary flexural compression failure. These indicating factors can also be used for Structural Health Monitoring (SHM) of civil infrastructure systems (e.g. bridges) to identify structural changes. In this context, non-destructive testing (NDT) methods offer different techniques for measuring deflections or crack formation and opening. However, profound knowledge on the determining failure modes of bending beams and their detection by NDT methods is required for the reliable application of SHM. Different NDT methods have been used in this study for analysing the load-bearing behaviour of a reinforced concrete beam in bending. The different measuring techniques are briefly described and their applicability is discussed by means of experimental results. For this purpose, the load-bearing behaviour of a reinforced concrete beam having a span of 2.75 m was investigated in a four-point bending flexural test at laboratory scale. The focus is on the characterization of determining failure modes by optical NDT and the comparison with classical measuring techniques (e.g. deformation measurements by displacement transducers). The bending beam was equipped with two single-mode (SM) sensor fibres. One fibre served as Distributed Optical Fibre Sensor (DOFS), whereas the other fibre contained Fibre Bragg Grating (FBG) sensors. In addition, optical deformation measurements using Digital Image Correlation (DIC) and Stereophotogrammetry (SP) were conducted. KW - Concrete beam KW - Bending KW - Digital image correlation KW - Stereophotogrammetry KW - Distributed fibre optic sensor KW - Fibre bragg grating PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-524762 VL - 54 IS - 3 SP - Article 102 PB - Springer AN - OPUS4-52476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nery de Araújo Neto, Gilberto A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten ED - Grantham, Michael ED - Basheer, P. A. Muhammed ED - Magee, Bryan ED - Soutsos, Marios T1 - Design of a cementitious coating system for corrosion protection: Phase 1 binder materials selection N2 - This paper presents the first results of an ongoing research project on the development of a cementitious thin layer coating system with high resistance against chloride penetration and carbonation. It is intended to display the decision process used for selecting raw materials as well as the conclusions based on test results and theoretical deliberations. In this phase, only the influence of the binder materials was analyzed concerning mechanical properties. The system should enhance the durability of new and old concrete structures exposed to aggressive environments, be based on market available materials and fulfill the requirements of the German guideline for concrete repair (Rili-SIB). T2 - Concrete Solutions 5th International Conference on Concrete Repair CY - Queen’s University Belfast, Northern Ireland, UK DA - 01.09.2014 KW - Concrete repair KW - Durability KW - Chloride penetration KW - Carbonation PY - 2014 SN - 978-1-138-02708-4 SN - 978-1-315-73731-7 U6 - https://doi.org/10.1201/b17394-66 SP - Chapter 60, 423 EP - 429 PB - CRC Press AN - OPUS4-40114 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pirskawetz, Stephan A1 - Hüsken, Götz A1 - Gründer, Klaus-Peter A1 - Kadoke, Daniel ED - Bohse, Jürgen ED - Purschke, Matthias T1 - Analyse der Schadensmechanismen biegebeanspruchter Stahlbetonbalken mittels zerstörungsfreier Prüftechniken N2 - Der durch Kräfte senkrecht zur Stabachse belastete Balken ist eines der Haupttragelemente des Stahlbetonbaus. Biegebalken finden unter anderem Anwendung in Form von Brückenträgern oder Unterzügen. Die bei maximaler Beanspruchung auftretenden Versagensformen unterteilen sich dabei in Biege- und Querkraftversagen (Schubversagen). Ein Versagen des Balkens kann je nach Versagensmechanismus mit oder ohne Vorankündigung erfolgen. Gebräuchliche Bemessungskonzepte der Baupraxis zur Dimensionierung entsprechender Tragelemente zielen auf ein Versagen mit ausreichender Vorankündigung (große Verformungen oder breite Risse) ab, wie es z.B. beim sekundären Biegedruckversagen entsteht. Für die Zustandsüberwachung von Bauwerken (z.B. Brücken) mittels zerstörungsfreier Prüftechniken sind fundierte Kenntnisse zu den bei Biegebeanspruchung auftretenden Schadensmechanismen erforderlich. Im Rahmen eines BAM-internen Projektes sollen durch praxisnahe Untersuchungen an einer brückenähnlichen Referenzstruktur unterschiedliche auf das Tragwerk einwirkende thermische und mechanische Belastungen untersucht werden und in die Entwicklung eines Monitoringsystems einfließen. Anhand der aus Biegeversuchen vorliegenden Ergebnisse wird der Einsatz unterschiedlicher Methoden der zerstörungsfreien Materialprüfung gezeigt und deren Anwendbarkeit für die Analyse des Verformungsverhaltens von Stahlbetonbalken diskutiert. Hierzu wurde das Verformungsverhalten eines Stahlbetonbalkens (L = 2,75 m) in einem Vierpunkt-Biegeversuch im Labormaßstab untersucht. Das Hauptaugenmerk liegt dabei auf der Charakterisierung der ausschlaggebenden Versagensmodi durch die einzelnen zerstörungsfreien Prüfverfahren und der Vergleich zu klassischen Messmethoden (z.B. Verformungsmessung mittels induktiver Wegaufnehmer (IWA)). Die Biegeversuche wurden dazu durch Schallemissionsanalyse (SEA) und optische Verformungsanalyse mittels Stereo-Fotogrammetrie (SF) und Bildkorrelationsverfahren (BKV) begleitet. T2 - 21. Kolloquium Schallemission CY - Fulda, Germany DA - 09.03.2017 KW - Optische Verformungsanalyse KW - Rissbildung KW - Schallemission KW - Stahlbeton KW - Tragverhalten bei Biegebeanspruchung PY - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-393617 SN - 978-3-940283-82-5 VL - 59 SP - 1 EP - 10 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-39361 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Meinel, Dietmar ED - Banjad Pecur, Ivana ED - Baricevic, Ana ED - Stirmer, Nina ED - Bjegovic, Dubravka T1 - Experimental characterization of the fracture behavior of UHPFRC N2 - Ultra-high performance fiber-reinforced concretes (UHPFRCs) are most suitable for applications with extreme mechanical loads. These extreme conditions require ductile behavior under tensile loading, which is obtained solely by the working mechanism of steel fibers. Profound knowledge on the working mechanism of the steel fibers is necessary to optimize this material. Usually, this knowledge is obtained by means of classical destructive measuring techniques. Adopting measuring techniques from non-destructive material testing helps to analyze and to identify the different stages of the fracture mechanism of UHPFRC in detail. The application of different non-destructive measuring techniques is shown exemplary on tensile tests conducted on an UHPFRC mix and its applicability for analyzing the fracture behavior of such concretes is discussed. The main focus is on the characterization of the relevant failure modes under tensile loading by the different measuring techniques and the comparison with classical measuring techniques (e.g. extensometer). The tensile tests have been analyzed by optical deformation measurements using digital image correlation (DIC), acoustic emission analysis (AE), and 3D computed tomography (CT). T2 - 1st International Conference on Construction Materials for Sustainable Future (CoMS_2017) CY - Zadar, Croatia DA - 19.04.2017 KW - UHPFRC KW - Tensile strength KW - Acoustic emission analysis KW - Optical deformation measurement KW - 3D computed tomography PY - 2017 SN - 978-953-8168-04-8 SP - 293 EP - 299 AN - OPUS4-39910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Meinel, Dietmar T1 - Experimental characterization of the fracture behavior of UHPFRC N2 - Ultra-high performance fiber-reinforced concretes (UHPFRCs) are most suitable for applications with extreme mechanical loads. These extreme conditions require ductile behavior under tensile loading, which is obtained solely by the working mechanism of steel fibers. Profound knowledge on the working mechanism of the steel fibers is necessary to optimize this material. Usually, this knowledge is obtained by means of classical destructive measuring techniques. Adopting measuring techniques from non-destructive material testing helps to analyze and to identify the different stages of the fracture mechanism of UHPFRC in detail. The application of different non-destructive measuring techniques is shown exemplary on tensile tests conducted on an UHPFRC mix and its applicability for analyzing the fracture behavior of such concretes is discussed. The main focus is on the characterization of the relevant failure modes under tensile loading by the different measuring techniques and the comparison with classical measuring techniques (e.g. extensometer). The tensile tests have been analyzed by optical deformation measurements using digital image correlation (DIC), acoustic emission analysis (AE), and 3D computed tomography (CT). T2 - 1st International Conference on Construction Materials for Sustainable Future (CoMS_2017) CY - Zadar, Croatia DA - 19.04.2017 KW - UHPFRC KW - Tensile strength KW - Acoustic emission analysis KW - Optical deformation measurement KW - 3D computed tomography PY - 2017 AN - OPUS4-39913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shamsuddoha, Md A1 - Baeßler, Matthias A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Kühne, Hans-Carsten A1 - Thiele, Marc ED - Banjad Pecur, Ivana ED - Baricevic, Ana ED - Stirmer, Nina ED - Bjegovic, Dubravka T1 - Identification of failure pattern in cylindrical grouted connection for wind structures - a pilot study N2 - At present, Wind Turbine Generators (WTGs) operating in onshore and offshore wind farms are primary sources of renewable energy around the world. Cylindrical grouted sleeve connections are usually adopted in these WTG structures to connect the upper structure and foundation for ease of installation. These structures including grouted connections experience considerable adverse loading during their lifetimes. Settlements were reported inside similar connections used in energy structures especially oil and gas platforms, which were installed in last three decades. Thus, repair and rehabilitation of such connections in existing wind structures should also be planned ahead to keep them operating in the future. The nature of failure and crack generation in grouted connections are crucial prior to adopt a strengthening strategy. This pilot study is carried out to actualize the failure mechanism in the grouted connection, when subjected to axial loading. A novel reusable scaled cylindrical grouted connection with shear keys was designed and tested for its load bearing behaviour. The mechanical test was accompanied by classical measuring techniques (e.g. displacement transducer) as well as non-destructive measuring techniques (e.g. digital image correlation (DIC), acoustic emission analysis (AE)). The failure mechanism incorporating slippage of the shear keys and cracking of the grout was investigated. The capacity and applicability of such test mould were also discussed. The knowledge is expected to pave way towards repair of deteriorated grouted connections with similar geometry and failure pattern. T2 - 1st International Conference on Construction Materials for Sustainable Future (CoMS_2017) CY - Zadar, Croatia DA - 19.04.2017 KW - Grouted connections KW - Cracks KW - Failure KW - Strengthening strategy KW - Digital image correlation KW - Acoustic emission analysis PY - 2017 SN - 978-953-8168-04-8 SP - 544 EP - 551 AN - OPUS4-39914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Shamsuddoha, Md A1 - Pirskawetz, Stephan A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten A1 - Thiele, Marc T1 - Identification of failure pattern in cylindrical grouted connection for wind structures – a pilot study N2 - At present, Wind Turbine Generators (WTGs) operating in onshore and offshore wind farms are primary sources of renewable energy around the world. Cylindrical grouted sleeve connections are usually adopted in these WTG structures to connect the upper structure and foundation for ease of installation. These structures including grouted connections experience considerable adverse loading during their lifetimes. Settlements were reported inside similar connections used in energy structures especially oil and gas platforms, which were installed in last three decades. Thus, repair and rehabilitation of such connections in existing wind structures should also be planned ahead to keep them operating in the future. The nature of failure and crack generation in grouted connections are crucial prior to adopt a strengthening strategy. This pilot study is carried out to actualize the failure mechanism in the grouted connection, when subjected to axial loading. A novel reusable scaled cylindrical grouted connection with shear keys was designed and tested for its load bearing behaviour. The mechanical test was accompanied by classical measuring techniques (e.g. displacement transducer) as well as non-destructive measuring techniques (e.g. digital image correlation (DIC), acoustic emission analysis (AE)). The failure mechanism incorporating slippage of the shear keys and cracking of the grout was investigated. The capacity and applicability of such test mould were also discussed. The knowledge is expected to pave way towards repair of deteriorated grouted connections with similar geometry and failure pattern. T2 - 1st International Conference on Construction Materials for Sustainable Future (CoMS_2017) CY - Zadar, Croatia DA - 19.04.2017 KW - Grouted connections KW - Cracks KW - Failure KW - Strengthening strategy KW - Digital image correlation KW - Acoustic emission analysis PY - 2017 AN - OPUS4-39915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten T1 - Bemessung und Ausführung von Groutverbindungen nach DIN 18088-5 N2 - Die Grout-Verbindung stellt die Nahtstelle zwischen Gründungsbauwerk und aufgehender Tragstruktur sicher. Die Funktion und Dauerhaftigkeit dieser Verbindung ist essentiell für die sichere Betriebsphase von Offshore-Windenergieanlagen. Die Bemessung der Grout-Verbindung stellt aktuell weitgehendes Neuland ohne Langzeiterfahrung dar. Gleichzeitig sind die Bedingungen bei der Montage Offshore sehr schwierig und die eingesetzten Materialien sind aufgrund ihrer technischen Merkmale in Verbindung mit den Verarbeitungsbedingungen nicht unproblematisch. Demzufolge stellen Grout-Verbindungen ungeregelte Bauarten und die hierfür verwendeten Mörtel (Grouts) ungeregelte Bauprodukte dar. Im Rahmen der Genehmigung ist daher beim Bundesamt für Seeschifffahrt und Hydrographie (BSH) als zuständiger Genehmigungsbehörde für jedes Bauvorhaben eine projektbezogene Zustimmung im Einzelfall (ZiE) zu beantragen. Vor diesem Hintergrund sollte im DIN-Arbeitsausschuss NA 005-51-07 AA "Windenergieanlagen" eine geschlossene Normenreihe für Tragstrukturen von Windenergieanlagen und Plattformen erarbeitet werden. Anhand der Normenreihe soll allen bei der Planung, Errichtung und dem Betrieb von Windkraftanlagen Beteiligten ein Regelwerk für Bemessung, Baustoffe und deren Verwendung zur Verfügung gestellt werden. Ein Verweis auf die Normenanforderungen bzgl. der stofflichen Anforderungen, Bemessung und Ausführung durch den betreffenden BSH-Standard ist möglich, da eine ZiE weiterhin notwendig ist. Jedoch kann der Genehmigungsprozess aufgrund der vereinheitlichten Randbedingungen vereinfacht werden. Nach der erfolgreichen nationalen Einführung der DIN 18088 soll die Harmonisierung auf europäischer Ebene erfolgen. T2 - Offshoretage 2017 CY - Heiligendamm, Germany DA - 15.03.2017 KW - Grout-Verbindung KW - DIN 18088-5 KW - Offshore-Windenergieanlagen PY - 2017 AN - OPUS4-39634 LA - deu 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 U6 - 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 - Shamsuddoha, Md A1 - Hüsken, Götz A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten A1 - Thiele, Marc T1 - Critical factors affecting the capacity of cylindrical grouted connections in offshore energy structures N2 - Current trend suggests that global energy consumption will increase in the future. This growing energy demand and advancement of technology lead to explore all potential offshore fossil and non-fossil energy sources, necessitating erection of exploration and production structures, rigs, platforms and towers, which are susceptible to adverse environmental conditions along with their maintenances. Cylindrical grouted joints provide suitable connections between steel substructure and foundation in these offshore platforms and wind structures especially monopiles for ease of installation. However, these are composite connections with exterior sleeve, interior pile and infill grout. The capacity of these connections is affected by number of factors. The literature over last four decades by numerous researchers has shown the development of these connections with increasingly higher capacities and influences on these capacities due to various factors. This paper provides a comprehensive review on the factors affecting the connection capacity along with technical challenges for the future. Critical aspects and shortcomings of the current connection systems and potential solutions may be sought after for these issues are also discussed. T2 - 36th International Conference on Ocean, Offshore and Arctic Engineering CY - Trondheim, Norway DA - 25.06.2017 KW - Offshore wind energy KW - Grouted connection KW - Joint capacity KW - Shear keys PY - 2017 SN - 978-0-7918-5766-3 U6 - https://doi.org/10.1115/OMAE2017-62510 VL - 3B SP - UNSP V03BT02A037, 1 EP - 10 AN - OPUS4-42387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pirskawetz, Stephan A1 - Hüsken, Götz A1 - Curosu, I. A1 - Mechtcherine, V. ED - Mechtcherine, V. ED - Slowik, V. ED - Kabele, P. T1 - Combination of Digital Image Correlation and Acoustic Emission for Characterizing Failure Modes in Strain-Hardening Cement-Based Composites (SHCC) N2 - The tensile behavior of strain-hardening cement-based composites (SHCC) is usually investigated on macroscopic scale by means of direct tension tests or bending tests. Additionally, the micromechanical properties of the composites are often described based on single fiber tension and pull-out tests. Such investigations, performed both on macroscopic and microscopic scales, are based on ‘classical’ force and displacement measuring techniques. Advanced test methods such as digital image correlation (DIC) and acoustic emission analysis (AE) may facilitate the identification and the analysis of the failure mechanisms in SHCC, which is important for both monitoring loaded SHCC elements and further material development and optimization. In this study, these two techniques are combined to characterize the failure mechanisms of three different types of SHCC in direct tension tests. The results are related to data of stress and strain measurements. It is shown that DIC provides detailed spatially resolved and stress related strain measurements. Furthermore, it is demonstrated that AE allows for the localization of active cracks, quantification of the damage accumulation under increasing stresses, and characterization of the dominant crack bridging mechanisms and failure modes observed in the different types of SHCC. T2 - 4th International RILEM Conference on Strain-Hardening Cement-Based Composites (SHCC4) CY - Technische Universität Dresden, Germany DA - 18.09.2017 KW - Cementitious composites KW - Strain-hardening KW - Fiber reinforcement KW - Tension KW - Multiple cracking KW - Acoustic emission analysis KW - Digital image correlation PY - 2017 SN - 978-94-024-1194-2 U6 - https://doi.org/10.1007/978-94-024-1194-2 VL - 15 SP - 300 EP - 307 PB - Springer Science+Business Media B.V. CY - Dordrecht, The Netherlands AN - OPUS4-42129 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shamsuddoha, Md A1 - Hüsken, Götz A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Baeßler, Matthias T1 - Ternary mix design of grout material for structural repair using statistical tools N2 - Repair is an indispensable part of the maintenance of structures over their lifetimes. Structural grouting is a widely used remediation technique for concrete components, trenches, mine subsidence, dam joints, restoration of masonry structures, and geological stabilizations. A structural grout system should be injectable in narrow spaces and hence include ingredients with finer particles. Ultrafine cements are ideal for these type of demanding grouts due to their superior properties compared to that of the less expensive, but coarser ordinary Portland cement (OPC). Supplementary cementitious materials (SCMs) are often used to replace OPC clinker based binder in order to modify certain properties and to reduce costs. The most commonly used SCMs are fly ash (FA), and ground granulated blast furnace slag (GGBS). For various special applications microsilica (MS), and metakaolin (MK) are also used. Identifying the optimum replacement contents of OPC by SCMs are a challenge during the design of such grouts. The aim of this experimental study is to investigate the effect of the selected SCMs (FA, MS and MK) on the slump flow, time of efflux, viscosity, shrinkage, and compressive and flexural strength of ultrafine cement based grouts with constant water-binder ratio and superplasticizer content. The test program was formulated using Box-Behnken design principles. Maximum percentages of replacement with ultrafine cement was 6% by volume of cement for MS and 16% for FA, and MK. The results suggest that most investigated grouts have the potential to be used for structural applications. The appropriate quadratic models are then formulated through statistical tools and presented as response surfaces. The trends indicate that fly ash improves the rheological properties, whereas microsilica and metakaolin positively affect shrinkage and mechanical properties to some extent. Based on the influence of SCMs and priorities among the properties, Decision Matrix Analysis (DMA) is carried out to select the most suitable ones among the SCMs. The analysis suggests that microsilica and fly ash are more suitable as SCMs than metakaolin without affecting the properties. KW - Grouting KW - Microsilica KW - Fly ash KW - Metakaolin KW - Workability KW - Viscosity KW - Strength KW - Mix design KW - Box-Behnken KW - Decision matrix analysis PY - 2018 U6 - https://doi.org/10.1016/j.conbuildmat.2018.08.156 SN - 0950-0618 SN - 1879-0526 VL - 189 SP - 170 EP - 180 PB - Elsevier Ltd. AN - OPUS4-45922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shamsuddoha, Md A1 - Hüsken, Götz A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Baeßler, Matthias ED - Alexander, M.G. ED - Beushausen, H. ED - Dehn, F. ED - Moyo, P. T1 - Workability and mechanical properties of ultrafine cement based grout for structural rehabilitation: A parametric study on the partial replacement with SCMs N2 - Grouting is a universal repair and strengthening technique, which is constantly used for structural remediation of concrete components, trenches, mine subsidence, dam joints, restoration of masonry structures, and geological stabilizations. Having an extremely small particle size of only few microns, ultrafine cements are ideal for grouting applications due to their superior permeability and compressive strength properties of the hardened cement paste compared to that of the less-expensive, but coarser ordinary Portland cements. Supplementary cementitious materials (SCMs) are often used to replace ultrafine cement in order to modify certain properties and to reduce costs. The aim of this experimental study is to investigate the effect of three supplementary materials: microsilica (MS), fly ash (FA), and metakaolin (MK) on the workability, and mechanical properties of an ultrafine cement based grout with a constant water-binder ratio and constant superplasticizer content. Maximum percentages of replacement with ultrafine cement were 6% by volume of cement for MS and 16% for FA, and MK. In general, results suggest that the workability is improved by addition of FA, whereas is reduced, when modified with MS and MK. The compressive strength of grout after cement replacement remains comparable to that of pure cement grout. However, there is a tendency of the MS to positively affect the compressive strength opposite to FA, whereas flexural strength is positively affected by FA. Based on the results, it is evident that grouts with Hägerman cone flow more than 500 mm and compressive strength of more than 90 MPa after 28 days can be produced. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2018) CY - Cape Town, South Africa DA - 19.11.2018 KW - Grouting KW - Repair KW - Box-Behnken KW - Supplementary cementitious materials KW - Analysis of variance PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-464769 SN - 2261-236X VL - 199 SP - 07006-1 EP - 07006-7 PB - MATEC Web of Conferences AN - OPUS4-46476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pirskawetz, Stephan A1 - Hüsken, Götz A1 - Gründer, Klaus-Peter A1 - Kadoke, Daniel ED - Caspeele, R. ED - Taerwe, L. ED - Frangopol, D. M. T1 - Damage mechanisms analysis of reinforced concrete beams in bending using non-destructive testing N2 - Beams that are loaded in transverse direction are one of the main structural elements used in reinforced concrete structures. Bending beams are used, for example, in bridge girders or joists. The strength related failure modes at maximum loading can be divided into bending and shear failure that could occur with or without indication. Conventional design concepts used in practice for designing structural elements subjected to bending aim at failure modes with sufficient indication (e.g. large deflections or cracks), as it occurs in the case of secondary flexure-compression-failure. These indicators can also be used to identify structural changes of civil infrastructure systems (e.g. bridges) using non-destructive testing methods for Structural Health Monitoring (SHM). However, profound knowledge on the determining failure modes of bending beams is required for the reliable application of structural health monitoring. Therefore, resulting effects of different thermal and mechanical loads on the response of a structure are investigated by means of a bridge demonstrator. The results of this investigation are used for developing a monitoring system. Different non-destructive testing (NDT) methods have been used for analyzing the deformation behavior of a reinforced concrete beam in bending. The suitability of the different measuring techniques will be discussed by means of the obtained experimental results. For this purpose, the deformation behavior of a reinforced concrete beam having a span of 2.75 m was investigated in a four-point bending flexural test at laboratory scale. The focus is on the characterization of determining failure modes by the NDT methods and the comparison with classical measuring techniques (e.g. deformation measurements by displacement transducers). The bending tests have been accompanied by Acoustic Emission analysis (AE), optical deformation measurements using Stereophotogrammetry (SP) and Digital Image Correlation (DIC). The conducted tests have shown that the three-dimensional detection of deformations and resulting strains with optical techniques is beneficial for analyzing the damage mechanism of loaded structures and related crack formation and propagation. Optical techniques can be supplemented by acoustic emission testing which gives detailed information on crack formation and progressing damage. The combination of both techniques offers the application as efficient monitoring system for larger structures. T2 - Sixth International Symposium on Life-Cycle Civil Engineering (IALCCE 2018) CY - Ghent, Belgium DA - 28.10.2018 KW - Concrete Beam KW - Bending KW - Digital Image Correlation KW - Stereophotogrammetry KW - Acoustic Emission Analysis KW - Non-Destructive Testing PY - 2019 SN - 978-1-138-62633-1 SN - 978-1-315-22891-4 SP - 2411 EP - 2417 PB - CRC Press AN - OPUS4-46439 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geißler, Peter A1 - Cuéllar, Pablo A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten A1 - Baeßler, Matthias T1 - Insights into compaction grouting for offshore pile foundations N2 - The authors are currently investigating the possibility to apply compaction grouting for offshore pile foundations (Jacket piles as well as monopiles) as a possible retrofitting technique for an optimised foundation concept. In this research project, we are developing a design approach aiming to predict the ideal amount and properties of a grout for a specific soil situation and desired improvement of pile bearing capacity after Installation and during service time. Both numerical and experimental tests have been carried out to investigate the injection process during which a highly viscous grout is injected into the soil under high pressure to displace and compact the surrounding soil without fracturing it. The implicit Material Point Method (MPM) based on a mixed formulation is the numerical technique chosen to deal with the expected large deformations and the arbitrary shape of the developing grout bulb. The usage of MPM prevents both the need of remeshing and the numerical instability induced by extensive mesh distortion. For validation with experimental results, we have constructed a testing chamber with one transparent sidewall. This chamber enables us to observe the injection process directly at the transparent vertical window and to measure the in-plane soil displacements and strains by means of the Digital Image Correlation (DIC) technique. The results already reveal the interrelation of soil and grout properties for a successful usage of this common ground improvement technique. T2 - 37th International Conference on Ocean, Offshore and Arctic Engineering (OMAE 2018) CY - Madrid, Spain DA - 18.06.2018 KW - Offshore pile foundation KW - Compaction grouting KW - Material Point Method (MPM) KW - Mixed formulation KW - Digital Image Correlation (DIC) PY - 2018 SN - 978-0-7918-5130-2 SN - 2153-4772 VL - 9 SP - V009T10A013, 1 EP - 9 AN - OPUS4-46004 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Shamsuddoha, M. A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Baeßler, Matthias T1 - Long-term mechanical and shrinkage properties of cementitious grouts for structural repair N2 - Grouts are particularly favoured in rehabilitation of structures due to penetrability and convenience of application. Grouts for repair applications typically require high-performance properties such as rapid strength development and superior shrinkage characteristics. Sometimes industrial by-products referred as supplementary cementitious materials (SCM) are used with neat cement due to their capabilities to provide binding properties at delayed stage. Micro silica, fly ash and metakaolin are such SCMs, those can modify and improve properties of cement products. This study aims at investigating long-term mass loss and linear shrinkage along with long-term compressive and flexural strength for grouts produced from ultrafine cement and SCMs. A series of mixtures were formulated to observe the effect of SCMs on these grout properties. Properties were determined after 365 days of curing at 23 °C and 55% relative humidity. The effect of SCMs on the properties are characterised by statistical models. Response surfaces were constructed to quantify these properties in relation to SCMs replacement. The results suggested that shrinkage was reduced by metakaolin, while micro silica and fly ash had positive effects on compressive and flexural strength, respectively. T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) CY - Rovinj, Croatia DA - 20.03.2019 KW - Grout KW - Long-term shrinkage KW - Micro silica KW - Fly ash KW - Metakaolin PY - 2019 AN - OPUS4-47625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shamsuddoha, Md A1 - Hüsken, Götz A1 - Schmidt, Wolfram A1 - Kühne, Hans-Carsten A1 - Baeßler, Matthias T1 - Superplasticizer and Shrinkage Reducing Admixture Dosages for Microfine Cement in Grout Systems N2 - Grouts have numerous applications including crack repair as maintenance in construction industries. Microfine cements are intensively used for high strength mortar and grout products. They are ideal for injection grouting in structural repair. Such grouts should have suitable rheological properties to be injectable, especially those used in repair and rehabilitation. The use of superplasticizers (SP) in these products is thus becoming increasingly crucial to achieve favorable workability and viscosity properties. A difficulty in such grouts is the plastic shrinkage due to finer particles used. It is thus necessary to determine optimum SP and shrinkage reducing admixture (SRA) dosages for a microfine cement based grout. In this study, a saturation dosage was decided from two Polycarboxylate ether (PCE) based SPs in relation to neat cement using slump flow and rheological parameters. A range of grout mixtures was formulated containing micro silica (MS) and fly ash (FA), and tested for suitable rheological and mechanical parameters. Based on the results, a grout mixture with MS and FA was selected to determine optimum SRA content. According to the results, a SP dosage of 3% by weight of neat cement is sufficient to achieve saturation. The grout material including MS and FA can produce comparable properties to neat cement grout. MS is found to improve compressive strength within the range considered, whereas a higher FA content provides favourable rheological properties. Finally, a SRA dosage of 4%, which could reduce the shrinkage by about 43% after 28d days, is determined for the grout system. T2 - 2nd International Conference on Building Materials and Materials Engineering (ICBMM 2018) CY - University of Lisbon, Portugal DA - 26.09.2018 KW - Grout KW - Microfine Cement KW - Superplasticizer KW - Supplementary Cementitious Materials KW - Shrinkage Reducing Admixture PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-478319 VL - 278 SP - Article Number 01001 PB - EDP Sciences AN - OPUS4-47831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sigrüner, M. A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Herz, J. A1 - Muscat, D. A1 - Strübbe, N. T1 - Pull-out behavior of polymer fibers in concrete N2 - The bond between polymer fibers and the surrounding cementitious matrix is essential for the development of concrete reinforcement. The single fiber pull-out test (SFPT) is the standard characterization technique for testing the bond strength. However, the different phases of debonding cannot be distinguished by the SFPT. This study investigates the debonding of different polymer fibers from the surrounding cementitious matrix with a modified SFPT and proposes methods to change the SFPT setup to generate more valuable information on the debonding mechanism. The SFPT was equipped with linear variable differential transformers (LVDT), digital image correlation (DIC) and acoustic emission (AE) analysis. The results demonstrate that the modified SFPT allows a better understanding of the different phases of debonding during fiber pull-out. Furthermore, bond strength values calculated by different methods reveal that the chemical bond of the investigated polymers is not different as reported by previous studies. Deformation measurements performed using LVDTs and DIC are suitable measuring techniques to characterize the debonding mechanism in SFPT. A correlation between recorded AE and debonding phases was not found. KW - Polymer Fibres KW - Concrete KW - Pull-Out Behaviour KW - Debonding Mechanism PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-582918 SN - 2642-4169 SP - 1 EP - 13 PB - Wiley Periodicals, LLC. AN - OPUS4-58291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Costard, René A1 - Agasty, Amit A1 - Kadoke, Daniel A1 - Kind, Thomas A1 - Hicke, Konstantin A1 - Hüsken, Götz T1 - Charakterisierung der Belastung und Schädigung von Stahlbetonprüfkörpern unter Explosionsbeanspruchung N2 - Zur Bewertung der Widerstandsfähigkeit von Schutzobjekten und Bauteilen gegen Explosionsbeanspruchung führt die Bundesanstalt für Materialforschung und -prüfung (BAM) regelmäßig Sprengversuche im Realmaßstab auf einem Testgelände durch. Solche Versuche sind planungs- und ressourcenintensiv, sodass sie zunehmend durch numerische Simulationen ergänzt bzw. ersetzt werden. Aktuelle Forschungsarbeiten zielen darauf ab, neue Berechnungsmethoden und Materialmodelle zu entwickeln, mit denen die Bestimmung der Bauteilantwort sowie die daraus resultierende Schädigung nach einem Explosionsereignis möglich sind. Zur Validierung solcher Ansätze ist es notwendig, systematische Versuche mit unterschiedlichen Szenarien durchzuführen, bei denen die relevanten Parameter mit Hilfe verschiedener Messmethoden aufgezeichnet werden. T2 - 44. Informationstagung Sprengtechnik CY - Siegen, Germany DA - 14.04.2023 KW - Explosivstoff KW - Explosionswirkung KW - Stahlbeton KW - Faseroptische Sensorik PY - 2023 SN - 0941 - 4584 VL - 45 IS - 2 SP - 11 EP - 14 AN - OPUS4-58109 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin A1 - Chruscicki, Sebastian A1 - Breithaupt, Mathias A1 - Costard, René A1 - Kind, Thomas A1 - Hüsken, Götz A1 - Agasty, Amit T1 - Measuring Dynamic Behavior and Damage Evolution of a Reinforced Concrete Wall Subjected to Explosive Blasts using Embedded Distributed Fiber Optic Sensors N2 - Results from highly dynamic and static strain measurements, respectively, using embedded distributed fiber optic sensors in a steel-reinforced concrete wall under explosive blast-loading are presented, detailing the structure’s dynamic behavior and the evolutions of cracks. T2 - 28th International Conference on Optical Fiber Sensors (OFS-28) CY - Hamamatsu, Japan DA - 20.11.2023 KW - Distributed acoustic sensing KW - DAS KW - Structural response KW - Blast experiment KW - Embedded fiber optic sensor PY - 2023 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-59096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Fiedler, Georg A1 - Schubert, Thomas A1 - Hille, Falk A1 - Hüsken, Götz A1 - Beckmann, Birgit A1 - Grunwald, Marcel A1 - Redmer, Bernhard A1 - Rogge, Andreas T1 - Investigation of multiple impact-damaged reinforced concrete structures as a reference for liquid penetration behavior and tomographic studies N2 - The structural integrity of outer reinforced concrete (RC) containments of nuclear power plants provides an essential shield against external hazards. If this containment is damaged by an impact event, such as an aircraft crash, the question arises to which degree the reinforced concrete containment still has its protective capability. This concerns both purely structural protection and protection against liquids penetrating the interior of the containment. Due to the dimensions of the containment structures, it is difficult to perform real scale impact experiments, so in the past decades plate geometries at medium scale have been used for investigations. Detailed investigations on the structural behaviour of RC members or RC plates subjected to impact loading have already been presented in Just et al., Hering, Hering et al., Bracklow et al., Hille et al. and Nerger et al. The following investigations deal with the single and multiple impact event (first hard impact and/or subsequent soft impact) on a RC specimen, which provides the basis for further investigations. A description of the test setup and the test procedure as well as a presentation of the test results from the impact tests are provided. Furthermore, the experimental program is presented, which the damaged RC specimens are to undergo to deal with the question of how much the impact-damaged RC structure has become permeable to liquid media, such as water and kerosene, depending on the intensity of the impact. The aim of these following investigations is to develop a test setup that can be applied to investigate the liquid penetration behaviour (LPB) of small, medium, and large-scale RC members. In addition to the liquid penetration experiments, the damaged specimens are to be examined by planar tomography to obtain the damage inside the specimen. The combination of damaging event, fluid penetration behaviour and tomography should enable a comprehensive understanding of the damage to the RC specimen. T2 - Conference: 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT) CY - Yokohama, Japan DA - 04.03.2024 KW - Drop tower KW - Hard impact KW - Soft impact KW - Multiple impact PY - 2024 SP - 1 EP - 10 PB - IASMiRT CY - Yokohama, Japan AN - OPUS4-59723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -