Economic and environmental assessment of high‐strength steel grades

Environmental impact awareness in civil engineering is nowadays an important concern. The last message from the IPCC (Intergovernmental Panel on Climate Change) was clear: significant actions are mandatory and urgent to achieve the objective to limit global warming to 1.5°C. The building sector is one of the most polluting industrial sectors for which economically viable solutions must be found to cut the emissions. The development of new production technologies can contribute to this aim by creating innovative and more sustainable materials. Amongst the new materials that appear on the steel market, high strength steels are a nice example as they offer higher strength to weight ratio of structural steel elements, resulting in material savings, lighter foundations, easier transportation, and erection. These multiple advantages explain why the use of high strength steels could lead to both significant carbon emission and cost savings. However, the production of such steels uses more alloying elements and sometimes they require more production energy than for regular grades. The aim of this paper is to estimate the relative prices and relative carbon emissions of high strength steels to evaluate whether they constitute sustainable materials. This paper demonstrates that, in many cases, the increase of relative prices and carbon emissions as function of yield strength can be negligible by contrast to the weight savings induced by using high strength steels.