INFLUENCE OF CONNECTION DETAILING IN COLD-FORMED STEEL FRAMES SHEATHED WITH FIBRE-CEMENT BOARDS

Modern construction has been driven by the need of sustainable development, leading to an increased use of modular building elements, such as sheathed cold-formed steel (CFS) panels. Those are utilized as the leading load bearing components in low- to mid-rise buildings given their high strength-to-weight ratio. Recent research has shown that cementitious sheathing boards can substantially increase the stiffness and loading capacity of CFS panels under lateral loads. However, current standards only cover the design of K- or X- bracings to increase the lateral stiffness of CFS panels. Therefore, it becomes critical to quantify the composite action in sheathed cold-formed steel panels induced to the panel by cementitious sheathing boards. As the wall-panel behavior is sequentially affected by the stiffness of individual connectors, it becomes crucial to characterize the connection behavior, given how the most obvious failure modes are expected within the board-fastener interface. This paper presents an experimental investigation on the shear behaviour of connections in CFS systems sheathed with fibre-cement boards employing two different types of fasteners (i.e., with and without wingtips), for a constant diameter of 4.8 mm. Recommendations were made with regards to the influence of the fastener type in the ultimate capacity of the connection.