This thesis explores the environmental impact of the demolition and construction of viaducts using a Life Cycle Assessment (LCA) approach with the aim of proposing a framework for decision-makers and engineers to reduce the emissions related to construction and demolition projects, contributing to the development of more sustainable and durable infrastructures. The analysis examines all stages of the structure's life cycle from material extraction, construction, service life, and maintenance to end-of-life disposal. Particular focus is placed on the carbon footprint generated throughout these phases which is measured in terms of CO2 equivalent (CO2e) emissions since it represents the most significant parameter adopted in literature and provides a conversion criterion starting from all other relevant Greenhouse Gases (GHG).