Gleitfeste Verbindungen im Turm- und Mastbau - Prüfung und Beschichtung

Slip-resistant connection in towers and masts - testing and coating.

Bolted connections in towers and masts are executed as slip-resistant connections of categories B or C according to EN 1993-1-8 when deformations and slip have to be minimized, e. g. in radio masts and towers of wind turbines. The load bearing capacity of slip-resistant connections is mainly influenced by the level of preloading in the bolts and the friction of the faying surfaces - described by the slip factor. The highest possible and over the service life of the structure guaranteed slip resistance is desirable in order to keep the number of bolts and the faying surfaces of the complex and therefore expensive connections low and to meet the demand of the industry for maintenance-free connections. For these reasons, at present, extensive studies on the determination of the slip factor of slip-resistant connections on the basis of EN 1090-2 are carried out as part of the European RFCS research project SIROCO taking into account different preloading levels and coating types. Within the present contribution, first results are presented for alkali zinc silicate coated and zinc spray metallized faying surfaces.