Economic benefit of high strength steel sections for steel structures

The present work aims at studying the field of interest of high strength steel rolled sections (fy>460 MPa) for steel structures from an economic point of view. Whilst these high strength steel profiles do not exist yet, steelmakers are able to produce more resistant steels through more efficient production processes and a future emerging of these particular steel profiles is likely to occur. The use of this kind of steels can lead to a significant material saving. So, the use of high strength steel leads to lighter structures requiring smaller foundations, lower transportation and construction costs but also emitting less CO_2. However, buckling, fatigue or deflection requirements often reduce the advantage of high strength steels. It is for this reason that the designer is sometimes reluctant to use them. A study establishing the areas of economic benefit of high strength steel tubes in steel and composite structures had already been carried out at the University of Liège. The goal of the present is to extend this study to rolled sections (H-shape and I-shape). It therefore consists in providing methods in order to help the designer determining the economic benefit of high strength steel for structural elements subjected to different loadings. These ones are then used to determinate the areas of economic benefit of the high strength steels in comparison to regular steel, depending on their relative costs.