Strengthening of hot-rolled S355 steel I-section beams using WAAM high strength steel

An experimental investigation to assess the major-axis flexural behaviour of 12 hot-rolled S355 steel I-section beams strengthened by the addition of high strength steel (HSS) through wire arc additive manufacturing (WAAM) is presented. The geometry of the beam specimens was obtained by means of 3D laser scanning. The mechanical properties of both the hot-rolled and the WAAM steel were determined through monotonic tensile testing. Physical testing of the strengthened beam specimens was conducted. The results showed that the WAAM strengthening led to dramatic increases in bending resistances of between 35% and 80% under four-point bending, and of between 30% and 85% under three-point bending, for increases in mass of between just 5% and 15% respectively. At the same time, the specimens exhibited good ductility, despite the high strength of the WAAM additions. The presented experimental results, which are the first of their kind, successfully demonstrate the applicability of the proposed strengthening approach for both new and retrofitted steel beams, and the game-changing potential for enhancements in structural efficiency and reductions in embodied carbon in the construction industry. • Hot-rolled S355 I-section beams were strengthened using WAAM high strength steel. • Physical testing was conducted to evaluate major-axis flexural behaviour. • An 85% increase in bending moment resistance was achieved with only a 15% mass increase. • WAAM strengthening showed potential to reduce embodied carbon by approximately 30%.