Avaliação do ciclo de vida de pavimentos flexíveis com escória Sidercal® : estudos de caso

Abstract

The civil construction industry has a significant environmental impact, and using waste as a substitute for raw materials in pavement construction can represent a sustainable alternative. One way to assess environmental impacts is through Life Cycle Assessment (LCA). LCA is a methodology used to estimate potential environmental impacts throughout the entire life cycle of a product, from the extraction of raw materials to its final disposal. The research aims to conduct a comparative study of the LCA of 3 types of flexible pavements, one of which uses Sidercal® in the sub-base, and two pavements with materials commonly used in paving practices. Three segments of the BR-101 in Espírito Santo, Brazil, were analyzed for different types of pavements. The system boundaries extend from cradle to site, evaluating impacts through three impact methods and uncertainty analysis by the Monte Carlo method. Primary and secondary data were used; the latter includes literature information and the Ecoinvent 3.6 database. The results indicated that pavement A (with Sidercal®) had the best environmental performance among the three pavements evaluated. In the comparison between methods, pavement A was superior in all categories, except for mineral resource scarcity, in which there was a divergence between the chosen methods. The main impacts were caused by bituminous materials, bitumen, and asphalt emulsion. This suggests that to reduce environmental impacts, it is necessary to decrease the consumption of these materials or seek alternative sources. The section evaluation revealed that the impacts of pavements B and C (without slag) increase as the construction site moves away from Vitória. Pavement A demonstrated a significant reduction in the carbon footprint, saving more than 84,000 kg of CO2 eq per kilometer compared to the other pavements. The analysis of the maximum distance for slag transportation indicated a limit of 275 km from the industry to the construction site.