An investigation of a novel wood fibre-filled steel tubular (FFST) systems for construction

In recent years, the building industry has shown great interest in hybrid-timber construction. A smart combination of timber, steel and concrete can produce building structures that not only have a less environmental impact and lower carbon footprint, but also bring lighter, taller (buckling-resilient), and long-spanning solutions. Moreover, efficient technologies can be used to rework or recycle wood products, such as fibres into hybrid modules to assist the growing trend towards a circular economy. In this study, small-scale hybrid steel-timber structural modules are developed by inserting dried wood fibre products inside cold-formed steel square hollow sections without using adhesive. Using this technique, fibre-filled steel tubular (FFST) beams, columns, and 2D frames were manufactured and tested. The experimental results indicate that the FFST columns have axial stiffness and strength by 44% and 55%, respectively, higher than steel-only columns, while the flexural stiffness and strength of the FFST beam are 8.5% and 28% higher, respectively than the steel-only beam. The weight-to-performance ratio for the FFST columns and beams is 19.03% and 58.82% higher than a steel-only columns and beams, respectively. The beam-to-column connections of the FFST frames showed sizeable ductility in flexure. The significant results as part of this paper, as well as ease of assembly, suggest that the proposed FFST frames can be up scaled and potentially be used in residential dwellings or similar low-rise applications.