The effects of structural design alternatives on the embodied carbon emissions of steel buildings

With the increasing number of steel structure buildings, its greenhouse gas (GHG) emissions have been a subject of lasting interest in regard to environmental sustainability. In this study, under the same seismic capacity, the effects of structural design alternatives (material strength and structural system) on the embodied carbon (EC) emissions at the product, construction process, and end-of-life stages of steel buildings in Taiwan were investigated. The investigation cases included 40-story office buildings using steels with varying strength levels and 6- and 20-story steel office buildings with different structural systems (moment-resisting frame (MRF), eccentric braced frame (EBF), and buckling-restrained braced frame (BRBF)). The EC coefficients at each life cycle stage were obtained via the analysis of big data from the literature. The results revealed that for buildings that partially use high-strength steel (SM570) versus buildings that entirely use general steel, the total amount of steel used was reduced, and the EC emissions were lower. For the different structural systems, regardless of the number of floors, the ranking of EC emissions from highest to lowest was MRF, EBF, and BRBF.