Sustainability life cycle design of bridges in aggressive environments considering social impacts

The establishment of the Sustainable Development Goals in 2015 claims for a deep paradigm shift in the way infrastructure structures are conceived. The evaluation of the impacts derived from the construction, the service and the end-of-life stages of an infrastructure is consequently in the spotlight of the research community. Being the construction sector as one of the main stressors of the environment, great attention has been recently paid to the structural design from the economic and the environmental point of view. However, sustainability requires to consider the social dimension as well. The evaluation of the social impacts of products is still at a very early stage of development, so the inclusion of social aspects in the design of structures is often overlooked. In this study, a comparison of life cycle assessment results is conducted on seven different design alternatives for a bridge in a coastal environment. Two approaches are followed: the first approach considers the economic and the environmental aspects of each design and the second approach includes the several social impacts specifically developed for the assessment of infrastructures. These social impacts account for four stakeholders, namely workers, consumers, local community and society. Results show that the inclusion of social aspects shall lead to different preferred options when compared with conventional, two-dimensional approaches. Here, the design with silica fume added concrete performs 11% better from a sustainability point of view when compared with the best solution resulting from a conventional assessment.