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The first, and probably the most determining, decision that engineering teams need to make when facing the structural design of any infrastructure is the choice of both an appropriate material and the suitable structural typology for its components. Each component is required to satisfy technical and functional aspects imposed by standards and stakeholder. Currently, the aspects that are most frequently considered in decision-making processes are economic. Nevertheless, environmental and social criteria are also required if one aims at making sustainability-based decisions. In this regard, to the best of the authors' knowledge, very few tools or studies exist that can support decision-makers. The few that do exist, are rather limited, either because they fail to incorporate many relevant factors in the sustainability assessment of a project or because they only evaluate environmental and social impacts of a project as a whole. Although a global assessment is useful to gain a holistic understanding of impacts of a project and to compare them to other projects, it does not necessarily help engineering teams understand the impact of fundamental decisions made when designing individual structural components. Therefore, the aim of the present research paper is to develop a new method for the sustainability analysis of building structural components which has been specifically oriented to beams and girders. This is done by means of the Integrated Value Model for the Evaluation of Sustainability method, which is known by its Spanish acronym, MIVES (Modelo Integrado de Valor para una Evaluación Sostenible). This method draws on multi-attribute utility theory and that allows building an integrated value model as an approach for multi-criteria decision-making. The developed model has been applied to assess the sustainability of different alternatives of beams and trusts to support the non-accessible roof of a sports hall in Vila-seca, Spain. Different material types and structural typologies are analysed. The findings show that the most sustainable alternatives are timber and reinforced concrete trusses, which are actually two options that are seldom used in practice. • A model to evaluate the sustainability of structural elements is developed. • MIVES is proved to be an adequate sustainability assessment tool in these cases. • Girders and trusses made of timber, concrete and steel are analysed. • Timber and concrete trusses achieve the highest global sustainability indexes. [ABSTRACT FROM AUTHOR]

The design of building foundations has usually been based on tradition, local practice, experience, and structural design codes. Safety is invariably considered the main factor and environmental criteria (or, in general, sustainability) is seldom given due consideration. However, similar safety indicators can be achieved with different variables and a minimum safety factor must always be ensured. The main objective of this study is, from an environmental perspective, to assess the influence of the construction system (cast-in-situ or precast), foundation type (rigid or flexible), and structural code (EC-2 or EHE-08) in the case of a concrete shallow foundation (CSF), using Life Cycle Assessment (LCA). Applying this methodology, the materials (concrete and steel) yielded the highest impacts in all categories, at around 95% for cast-in-situ CSFs and at around 85% for precast CSFs, both in relation to global warming. Consequently, optimization of the amount of these materials is crucial when considering the particular variables selected in this study. The results showed that cast-in-situ and flexible CSFs at moderately shallow depths (and therefore with less steel reinforcement) and precast CSFs with considerable reductions in concrete volumes (due to sloped shapes) had lower environmental impacts. In addition, cast-in-situ CSFs constructed in accordance with the EHE-08 structural code showed lower impacts, while precast CSFs complying with the EC-2 code were environmentally preferable. However, a specific study might be required for specific factors in each case (loads, soil type, structural settlement, among others). Relevant environmental effects associated with the three variables should therefore be given specific consideration in the development of structural design codes and future constructions. [ABSTRACT FROM AUTHOR]