In steel structures, bolted connections are preloaded either for load‐bearing capacity reasons or for serviceability reasons. Single and multi‐section connections of wind turbines, offshore plants, bridges etc. are typical application examples. Gap formation due to production‐ and assembly‐related imperfections poses a risk for a controlled application of the required preload level, which is vital for slip‐resistant and fatigue loaded connections. Furthermore, it might significantly affect the desired behaviour of the connection or even lead to premature failure. For this reason, EN 1090‐2 provides regulations on the allowable gap formation and even prescribes measures to avoid negative outcomes. One of the possibilities for a gap compensation are gap filling materials, also known as liquid shim or load transfer materials, such as MM1018 of DIAMANT Metallplastic GmbH, Germany, a two‐component composite system filled with special metallic materials. Currently, systematic investigations into the application of duroplastic gap filling materials in preloaded bolted connections are carried out in the frame of the German cooperation project “Bri‐San‐T ‐ DuroFüllSta”. Herein, the slip factor is experimentally determined according to EN 1090 2, Annex G under variation of application type, gap thickness, curing time, temperature and surface condition. Furthermore, relaxation tests are carried out to determine possible preload losses over the intended service life of the structure. The presented contribution intends to provide an insight into the main properties of duroplastic gap filling materials with regard to their application in preloaded bolted connections under various conditions.

The time factor plays one of the major roles in today's steel building. Particularly in the field of traffic infrastructure operational interruptions caused by assembly or repair work cause financial and economic trouble.New solutions for repair and assembly aimed at reducing costs and time are therefore in great demand, whether in the form of new materials or innovative application methods. A novel gap compensation material based on high strength polymers developed in Germany reduces time and cost in steel construction and assembly. The material works as a "liquid shim plate" and joins steel elements with a 100% force and form fit connection. The product can be applied in situ without machining or disassembly flexibility and safety for construction and maintenance works.The "liquid shim material" DIAMANT MM1018 is the first of its kind to be awarded the general building authority approval (abZ) by the German Institute of Building Technology (DIBt) [1] and approved by German railways (Deutsche Bahn) through intern regulation.The time factor plays one of the major roles in steel construction, either as the "tooth of time" with its unpleasant decaying character or in its dominating role "Time is money". No building or repair project can disregard the difficult time factor. This particularly shows in the field of traffic infrastructure. Operational interruptions caused by assembly or repair work cause financial and economic trouble.

Im Stahlbau werden Schraubverbindungen entweder aus Gründen der Tragfähigkeit oder der Gebrauchstauglichkeit vorgespannt. Ein‐ und mehrschnittige Verbindungen in Brücken, Funkmasten und Turmbauwerken von Windenergieanlagen gehören zu den typischen Einsatzgebieten. Eine Spaltbildung, hervorgerufen durch fertigungs‐ und montagebedingte Imperfektionen, stellt ein Risiko z. B. für das kontrollierte Aufbringen des erforderlichen Vorspannkraftniveaus sowie zur Vermeidung von Spaltkorrosion dar. Dies kann die Tragfähigkeit sowie die Dauerhaftigkeit der Verbindung erheblich beeinträchtigen und sogar zu einem vorzeitigen Versagen führen. Die Spaltbildung ist daher auf ein Minimum zu begrenzen, wobei DIN EN 1090‐2 dazu Maßnahmen wie z. B. den Einsatz von Futterblechen vorsieht. Eine mögliche Alternative für den Ausgleich von Spalten stellen Zweikomponenten‐Reaktionsharzsysteme auf Epoxidharzbasis dar, die zur Verbesserung der mechanischen Eigenschaften mit speziellen metallischen Werkstoffen gefüllt sind. Im Rahmen des ZIM‐Kooperationsprojekts „Bri‐San‐T – DuroFüllSta“ wurden systematische Untersuchungen zum Einsatz des duroplastischen Spaltausgleichsmaterials MM1018 der Firma Diamant Polymer GmbH in vorgespannten geschraubten Verbindungen durchgeführt. Im vorliegenden Beitrag werden die experimentell bestimmten Haftreibungszahlen sowie die zu erwartenden Vorspannkraftverluste vorgestellt.

Alumina is often used for electrical insulation. However, different material systems promise to increase the insulation due to their material characteristics. Because of the process properties including high cooling rates, thermally sprayed coatings generally differ from sintered material, which also effect the electrical properties. Within this study, different thermally sprayed coatings are analyzed via impedance spectroscopy to evaluate the capacitive and the electrical insulation behavior. Besides comparing the frequency-dependent resistance, equivalent circuit diagrams were used to calculate the relative permittivity of the coatings. X-ray diffractograms reveal the phase stability of the coatings during thermal spraying. X-ray diffraction was additionally conducted to classify the systems and the respective effects. In particular, the investigated mullite-based coatings exhibit slightly increased impedance values compared to conventionally used alumina-based coating systems.