Adhesively bonded steel tubes — Part I: Experimental investigations

Circular hollow sections (CHS) represent a class of tubular structural steel elements that enjoy great popularity among architects, and civil engineers. Connections thereof, however, remain complicated, despite significant developments in welding procedures. The first part of this series of two articles summarises research on adhesive bonding as a substitute to traditional joining techniques for tubular sections on a large scale. For that purpose, suitable adhesives have been selected and fully characterised, their adequacy for the required strength in combination with steel verified on lap shear samples, and finally corresponding adhesively bonded tubular joints tested in quasi-static loading with diameters from 42 mm (joint capacities from 55 kN) up to 300 mm (joint capacities up to 1’800 kN). Additionally to various diameters and overlap lengths considered, effects resulting from different types of imperfections, as axial and angular misalignment, on joint strength were experimentally investigated. Presented results clearly indicate that adhesive bonding is a joining technique adapted for civil engineering applications. The second part of this series presents a design methodology for adhesively bonded tubular joints that fits into the conceptual framework of civil engineering practice.