The 277 m high Baku Tower in Baku, the capital of Azerbaijan, is the tallest building in the Caucasus ever built. The tower is constantly subjected to enormous wind loads, that gave the city's name it's meaning “city of wind”. To cope with these wind loads a 400 t pendulum damper was installed on the tower's uppermost platform. Its special feature: in case of strong wind and earthquake, the 400 t mass block moves horizontally by up to 1.3 m in all directions in a controlled manner. This pendulum damper reduces the strain on the structure, thus it ensures the building's living and working comfort. The mass block consists of a massive steel box that was filled with concrete on site. MAURER not only manufactured the steel construction but also supervised the entire assembly and put the vibration damper into operation. (© Maurer SE)

Keine Kurzfassung verfügbar.

Keine Kurzfassung verfügbar.

Extended keynote paper of Eurosteel 2021
Automated production is finding its way into the fabrication of structural steel. One robot holds attachments (stiffeners, end plates, etc.) on a steel beam or column and another robot produces weld seams. However, welding robots can also be used for Additive Manufacturing (Wire and Arc Additive Manufacturing, WAAM). The wire electrode serves as a printing material. The Institute of Steel Construction and Materials Mechanics in Darmstadt is investigating how typical connecting elements for steel structures can be printed directly on steel beams using Additive Manufacturing with arc welding and robots. Furthermore, structural elements such as nodes for space frames can be printed and even complete structures, e.g. columns and a little bridge, have already been manufactured additively. The main focus is on determining suitable welding and process parameters. In addition, topology optimization is necessary in order to achieve good structures using a small amount of material. This is possible due to the free design prospects of WAAM, which opens up new design and production strategies.

Keine Kurzfassung verfügbar.

Extended keynote paper of Eurosteel 2021
The robustness of steel structures during severe earthquakes is largely based on the calibration of stiffness, strength and ductility. Such a robust system dissipates the energy by plastic deformations in the plastic members (fuses) made from mild carbon steel (MCS), while the other members remain elastic. In the case of concentrically braced frames (CBF), the fuses can be in the form of buckling-restrained braces (BRB), while for eccentrically braced frames (EBF), the short links could take on this role. In the case of shear walls (SW), slender steel plates can be used. To avoid oversized elastic members, they can be made of high-strength steel (HSS). Structures made from HSS and MCS are called dual steel (DS) structures. In order to ease the post-earthquake intervention, the fuses can be detachable. Furthermore, their replacement is less costly if the structure is re-centred using moment-resisting frames (MRF) connected to the main dissipative system, i.e. a dual frame (DF) structure. This paper presents the concept of DS DF structures and some examples.

Extended keynote paper of Eurosteel 2021
This two-part paper provides a state-of-art report on the most recent findings concerning the behaviour, strength and Direct Strength Method (DSM) design of cold-formed steel (CFS) columns and beams affected by mode coupling phenomena not adequately covered by the current specifications for CFS members, namely local-distortional (L-D), local-distortional-global (L-D-G), distortional-global (D-G) and global-global (flexural-torsional/flexural - FT-F) interaction. The paper addresses experimental tests, numerical simulations and DSM-based design approaches that are intended to i) acquire in-depth knowledge on the non-linear behaviour (elastic and elastic-plastic), load-carrying capacity and failure mode nature of the members under consideration, and ii) make use of that knowledge to develop, propose and assess the merit of efficient DSM-based design approaches to estimate their failure loads/moments. Initially, illustrative column results are briefly presented to help grasp some fundamental concepts, namely the characterisation of i) the aforementioned mode coupling phenomena, ii) different sources of mode interaction that may lead to failure load/moment erosion, and iii) the most detrimental initial geometrical imperfections. The DSM design curves currently codified and two strength curves recently developed for column flexural-torsional and beam distortional failures are presented next. The two-part paper then addresses separately each mode coupling phenomenon dealt with, for columns, but only L-D and D-G interaction for beams - while L-D interaction (in columns and beams) appears in Part 1, the remaining column and beam coupling phenomena (all involving global buckling) are dealt with in Part 2 [1]. For columns undergoing L-D and L-D-G interaction, beams experiencing L-D interaction and angle columns susceptible to FT-F interaction, the work reported includes experimental studies, numerical simulations and DSM-based design considerations and/or guidelines. For the remaining coupling phenomena, only numerical results are reported, but they unveil interesting (and unexpected) behavioural features that will help plan future test campaigns and achieve efficient design approaches. Finally, the two-part paper closes with a few concluding remarks and an outlook regarding future developments in this field.

Extended keynote paper of Eurosteel 2021
This is Part 2 of a two-part paper providing a state-of-art report of the most recent findings concerning the behaviour, strength and Direct Strength Method (DSM) design of cold-formed steel (CFS) columns and beams affected by mode coupling phenomena not adequately covered by the current specifications for CFS members. This second paper covers interactions involving global buckling modes, namely local-distortional-global (L-D-G), distortional-global (D-G) and global-global (flexural-torsional/flexural - FT-F) interaction - note that local-global (L-G) interaction, already well mastered by the technical/scientific community, is not dealt with. Like Part 1 [1], this paper also addresses experimental tests, numerical simulations and DSM-based design approaches, intended to i) acquire in-depth knowledge on the non-linear behaviour (elastic and elastic-plastic), load-carrying capacity and failure mode nature of the members under consideration, and ii) make use of the above knowledge to develop, propose and assess the merits of efficient DSM-based design approaches to estimate their failure loads/moments. Taking into account the fundamental concepts and DSM design curves presented in Part 1 [1], the paper addresses separately each mode coupling phenomenon dealt with, for columns, and only D-G interaction for beams - recall that L-D interaction (columns and beams) was covered in Part 1 [1]. For columns undergoing L-D-G interaction and angle columns susceptible to FT-F interaction, the work reported includes experimental studies, numerical simulations and DSM-based design considerations and/or guidelines. For columns and beams experiencing D-G interaction and channel columns prone to FT-F coupling, only numerical results are reported - they reveal surprising behavioural features that will be very useful in planning future test campaigns and achieving efficient design approaches. Finally, the two-part paper closes with a few concluding remarks and a perspective about future developments in this field.

Keine Kurzfassung verfügbar.

This two-part article gives an overview of the developments of the structural member verification in prEN 1993-1-1:2020 “Eurocode 3: Design of steel structures - part 1-1: General rules and rules for buildings”, one of the second generation of Eurocodes. These developments were undertaken by Working Group 1 (WG1) of Subcommittee CEN/TC250/SC3 and by Project Team 1 (SC3.PT1) responsible for drafting the new version of EN 1993-1-1. In the past, WG1 collected many topics needing improvement, and the systematic review conducted every five years also yielded topics needing further development. Based on this, the current version of EN 1993-1-1 has been developed into a new draft version prEN 1993-1-1:2020 enhancing “ease of use”. The technical content of this new draft was laid down at the end of 2019. Many improvements to design rules have been established with respect to structural analysis, resistance of cross-sections and stability of members. This two-part article focuses on member stability design rules and deals with the basis for the calibration of partial factors, the introduction of more economic design rules for semi-compact sections, methods for structural analysis in relation to the appropriate member stability design rules, new design rules for lateral torsional buckling plus other developments and innovations. This second part of the article is dedicated to illustrating the most relevant changes to member buckling design rules.

Keine Kurzfassung verfügbar.

Many mechanical joints in steel structures use conventional bolts. Nevertheless, this proven joining technology has some significant disadvantages. These basically include the high levels of scatter during application of the assembly preload using the torque-controlled tightening process, the risk of loosening during cyclic loads due to transverse displacement of the components and the low fatigue resistance under axial loading. Lockbolt technology was invented as long ago as the 1930s and mainly used for the aviation and space industry because of its evident advantages. This joining technology has been constantly further developed in response to the most diverse demands from sectors such as aviation, commercial vehicles, rail vehicles, agricultural machinery, defence technology and steel structures. The application of lockbolt technology, which is primarily used in mechanical engineering, was in most cases based on individual studies, since no consistent rules and guidelines were available for the design and execution of lockbolt connections in steel structures. Within the scope of several public research projects funded by the AiF (German Federation of Industrial Research Associations) and conducted by the iGF (Industrial Collective Research) organization as well as through approval investigations, the Fraunhofer Institute for Large Structures in Production Engineering (IGP) has successively developed the necessary design rules according to the EN 1993 standard (Eurocode 3) for use in structural connections. These design rules will be presented within the context of this article in order to make the benefits of this joining technology available to other users. In addition, insights into the use of technical approvals will be presented together with some current applications.

Nominated for the Professor Eduardo de Arantes e Oliveira Award at XII Conference on Steel and Composite Construction in Coimbra 2019
This paper presents the results of a numerical parametric study that investigated the M-V interaction behaviour of box-girder bridge deck specimens. The study made use of an advanced numerical model that was previously verified against the experimental results. Based on the numerical results and the current rules for trapezoidal box girders, new design models are proposed for predicting the bending and shear resistance of cross-sections with a curved bottom flange. Additionally, the force-based M-V interaction equation proposed by Jáger et al. [1], adopted in the new version of EN 1993-1-5 [2], was verified and slightly modified to fit this type of cross-section.

News:
Steel Construction increases CiteScore to 1.2

ECCS News:
D activities
ECCS Members Future activities - Events in 2020
News from Europe

People:
Obituary: Jerzy Ziółko

PHD-Thesis:
Fatigue Assessment of Large-Size Bolting Assemblies for Wind Turbine Support Structures

Keine Kurzfassung verfügbar.

Keine Kurzfassung verfügbar.

Zum Titelbild:
Dicke Außenwandkonstruktionen können zu Verlusten an Nutzfläche führen. Daher empfehlen sich Lösungen, welche neben einer hohen Dämmwirkung auch eine dünne Materialdicke aufweisen. Beispielsweise sind Resol-Hartschaumdämmplatten (Kingspan Kooltherm) für unterschiedliche Wandaufbauten, wie Wärmedämmverbundsysteme (WDVS), zweischaliges Mauerwerk, vorgehängte hinterlüftete Fassaden (VHF), erhältlich. Sie sind schlank und weisen dabei eine Wärmeleitfähigkeit &lgr; von bis zu 0,020 W/(m · K) auf. Bei den Mehrfamilienhäusern in Bremen kamen sie zum Einsatz, siehe Meldung S. 94. (© Foto: Kingspan Insulation)

Keine Kurzfassung verfügbar.

Die wesentlichen Anforderungen an die energetische Qualität von Gebäuden werden in Deutschland bisher in der Energieeinsparverordnung (EnEV) formuliert. In absehbarer Zeit wird die EnEV durch das Gebäudeenergiegesetz (GEG) ersetzt. Beiden Regelwerken ist gleich, dass lediglich der Energiebedarf, resultierend aus der Nutzungsphase eines Gebäudes, zu bilanzieren ist. Der Energieaufwand für die Herstellung und Instandhaltung von Gebäuden sowie für den Rückbau und die Entsorgung von veralteten Gebäudekomponenten wird dabei außer Acht gelassen. In der Vergangenheit war diese Einschränkung vertretbar. Mit der Entwicklung hocheffizienter Gebäude sinkt jedoch der Energiebedarf in der Nutzungsphase in hohem Maße und eine Neubewertung ist erforderlich. Wissenschaftliche Untersuchungen am Beispiel eines Ein- und eines Mehrfamilienhauses, welche die aktuellen Anforderungen der EnEV erfüllen, haben ergeben, dass über einen Zeitraum von 50 Jahren die Herstellungs- und Instandhaltungsphase zusammen einen Anteil von 30 % (EFH) bzw. 38 % (MFH) des gesamten Primärenergiebedarfs, nicht erneuerbar verursacht. Für diesen Anteil sind jedoch bisher keine gesetzlichen Vorgaben zu beachten. Es sind somit über die Gebäudenutzungsphase hinaus erhebliche Einsparpotenziale im Baubereich vorhanden. Zur Aktivierung dieser Potenziale werden im Rahmen dieses Artikels Ansätze zur Berücksichtigung der Herstellungs-, Nutzungs- und Instandhaltungsphase bei der energetischen Bewertung von Gebäuden vorgestellt.

Further development of the Energy Saving Ordinance - Approaches for taking into account the manufacturing, use and maintenance phase of buildings
The main requirements for the energetic quality of buildings in Germany are defined by the Energy Saving Ordinance (EnEV). In the foreseeable future, it will be replaced by the Building Energy Act (GEG). Both regulations account only for the energy demand resulting from the use phase of a building. The energy expenditure for the manufacture and maintenance of buildings and for the removal and disposal of old building components is not taken into account. In the past, this limitation was justifiable. However, with the development of highly efficient buildings, the energy demand of the use phase is decreasing significantly and a reassessment is necessary. Scientific investigations on the example of a single-family house and an apartment building, which fulfil the current requirements of the EnEV, have shown that over a period of 50 years the manufacturing and maintenance phase account for 30 % (single-family house) resp. 38 % (apartment building) of the total primary energy demand, non-renewable. However, there are no legal requirements yet to be observed for this share. This means that there is significant potential for savings in the building sector beyond the building use phase. In order to activate these potentials, this article presents approaches to consider the manufacturing, use and maintenance phase in the energy assessment of buildings.

Die Arbeitswelt hat sich in den letzten Jahrzehnten stark verändert. Heutzutage werden viele Büros, Besprechungsräume, aber auch andere Räume wie Vorlesungssäle, Unterrichtsräume sowie Hotelzimmer nur noch temporär genutzt. Die thermische Konditionierung orientiert sich jedoch immer noch an stationären Temperatursolllinien. Dies bedeutet, dass eine entsprechende Solltemperatur bereits vor Eintreffen des Nutzers im Raum erreicht sein und über den gesamten Arbeitstag vorgehalten werden muss, unabhängig davon, ob sich tatsächlich ein Nutzer im Raum aufhält. Adaptive Fassaden mit integrierten Heiz- bzw. Kühlelementen sind dazu in der Lage, sich verändernden Bedingungen, z. B. aufgrund von temporärer Nutzung eines Arbeitsplatzes, lokal und ohne Zeitverzögerung anzupassen, und so eine optimale Aufenthaltsqualität sicherzustellen. So ist während der Heizperiode ein deutlich niedrigeres Temperaturniveau ausreichend und sobald der Nutzer im Raum eintrifft, können durch Einschalten der lokalen Heizung unverzüglich behagliche Bedingungen hergestellt werden. Dies birgt insbesondere im Ultraleichtbau ein großes Energieeinsparpotenzial in sich. In vorangegangenen Untersuchungen wurde die thermischen Behaglichkeit unter transienten Bedingungen [1] beleuchtet sowie die bauphysikalische Funktionalität und Umweltwirkung einiger Beispiele auf Bauteil- sowie auf Raumebene von adaptiven Leichtbaukonstruktionen [2, 3] behandelt. Aufbauend auf diesen Erkenntnissen wurden Szenarien für den Betrieb von adaptiven Fassadenelementen mit lokalen Heizsystemen entwickelt. Im hier vorliegenden Beitrag wird nun das energetische Einsparpotenzial der lokalen Systeme gegenüber der konventionellen Raumheizung betrachtet.

Energy saving potential of adaptive façade elements for local heating - a parameter study
The working world has been changing in recent decades. Nowadays, many offices, meeting rooms but also other rooms, such as lecture halls, classrooms and hotel rooms, are only used temporarily. However, thermal conditioning is still based on temperature baselines in steady state. This means that a corresponding set temperature must be reached before the user arrives in the room and must be maintained for the entire working period, regardless of the presence of the user. Adaptive facade with integrated heating or cooling elements is able to adapt to changing conditions, i.e. due to temporary use of a workplace, locally and without time delay and thus ensures an optimal quality of stay. Furthermore, a significantly lower temperature level is sufficient during the heating period. As soon as the user arrives in the room, comfortable conditions can be created immediately by switching on the local heating system. This holds a great potential for energy saving, especially in ultra-lightweight construction. In previous investigations, the thermal comfort under transient conditions [1] was illuminated and the building physical functionality and environmental impact of some examples of adaptive lightweight structures [2, 3] at building component and room level were discussed. Based on these findings, scenarios for the operation of adaptive facade elements with local heating systems were developed. In this present article, the energy saving potential of the local systems is compared to conventional heating.

Keine Kurzfassung verfügbar.

Gesamtziel des Forschungs- und Entwicklungsvorhabens war die Verfahrens- und Produktentwicklung hochdämmender, kostengünstiger Bauelemente geringer Dicke mit Glasfaserstützkern sowie die Entwicklung und Erprobung konstruktiver und technologischer Lösungen für diverse Applikationen mit höchsten Anforderungen an die Wärmedämmung und Energieeffizienz.
Die Motivation für die durchgeführte Entwicklung ergab sich aus dem dringenden Bedarf an dünnen, kosteneffektiven, hochisolierenden Materialien in verschiedenen Anwendungsbereichen zur Erhöhung der Energieeffizienz durch Minimierung von Energieverlusten. Die steigenden Isolationsanforderungen (u. a. gegeben durch EnEV 2014/2016, Pariser Klimaabkommen) können mit herkömmlichen Dämmmaterialien wie Mineralwolle, Polyurethanschaum oder extrudierter Polystyrolschaum aufgrund ihrer vergleichsweisen hohen Wärmeleitfähigkeiten (20-40 mW/mK) nicht erfüllt werden. Um hochisolierende Anforderungen zu erreichen, müssen hochdämmende Materialien mit extrem niedrigen Wärmeleitfähigkeiten verwendet werden, wie zum Beispiel Vakuum-Isolations-Paneele (VIP).
Ziel des Projektes war die Werkstoff- und Verfahrensentwicklung eines hochdämmenden (ca. 2,5 mW/mK), langlebigen (ca. 30 Jahre), temperaturbeständigen (ca. 300 °C), verletzungsbeständigeren Glasfaser-VIP sowie die Entwicklung innovativer Applikationen im Bereich Bauwesen (Innenwanddämmung), Behälterbau sowie Containerbau mit höchsten Anforderungen an die Wärmedämmung.

Development of a multifunctional interior wall insulation using highly insulating, thin, innovative glass fiber VIP
The overall objective of the R&D-project was the process and product development of highly insulating low-cost components of small thickness with a glass fibre support core as well as the development and testing of constructive and technological solutions for various applications with the highest demands on thermal insulation and energy efficiency.
The motivation for the development was the urgent need for thin, cost-effective, highly insulating materials in various application areas to in-crease energy efficiency by minimizing energy losses. The increasing insulation requirements (given by EnEV 2014/2016, Paris Climate Agreement) cannot be met by conventional insulation materials such as mineral wool, polyurethane foam or extruded polystyrene foam, due to their comparatively high thermal conductivity (20-40 mW/mK). To achieve high insulation requirements, highly insulating materials with extremely low thermal conductivity must be used, such as vacuum insulation panels (VIP).
The aim of the project was the material and process development of a highly insulating (approx. 2.5 mW/mK), durable (approx. 30 years), temperature-resistant (approx. 300 °C), injury-resistant glass fibre VIP as well as the development of innovative applications in the field of construction (interior wall insulation), container construction, container building with the highest demands on thermal insulation.

Im vorliegenden Beitrag werden Messungen und Berechnungen vorgestellt, die die Temperaturentwicklung in Betonzylindern aufgrund zyklischer Beanspruchung genau beschreiben. Die Messungen wurden in einem Versuchsstand, die Berechnungen im FEM-Programm ANSYS durchgeführt. Mithilfe der Temperaturmessungen konnten die Simulationen für die Temperaturentwicklung der Betonzylinder mit der verwendeten Betonrezeptur validiert werden. Die Untersuchungen lassen den Schluss zu, dass bei zyklischer Probekörperbelastung und der einhergehenden Probekörperdehnung Energie dissipiert wird und diese maßgeblich für die Erwärmung der Probe verantwortlich ist.

Measurement and simulation of the heating of fatigue loaded concrete specimens
This paper presents measurements and simulations that describe the temperature development in concrete cylinders due to cyclic loading. The measurements were carried out in a test stand, the simulations in the FEM program ANSYS. The simulations of the temperature development in the concrete cylinders with the used concrete recipe were validated using the temperature measurements. The investigations lead to the conclusion that energy is dissipated during cyclic test specimen loading and the accompanying test specimen elongation and that this is mainly responsible for the heating of the specimen.

Keine Kurzfassung verfügbar.

Aktuell:
Raumgewinn durch schlanke Dämmung
Fortbildung in Denkmalpflege und Altbauerneuerung
Teams des Solar Decathlon Europe 2021 in Wuppertal
Berechnungstool zur neuen DIN 1946-6 des FGK
Neues VDPM-Merkblatt für Dübel in WDVS
Richtlinie für die Planung und Ausführung von Abdichtungen mit flexiblen polymermodifizierten Dickbeschichtungen (FPD)” - FPD-Richtlinie - veröffentlicht
DIN 4109-5 für erhöhte Anforderungen an den Schallschutz verabschiedet
Das FIW warnt vor gefälschtem Prüfbericht Nr. F2-18-1702-01