Numerical method for carbon footprint assessment of recycled concrete aggregates

The construction sector is a major generator of atmospheric emissions and solid waste, denoting the need to account for its environmental impacts in contributing to climate change. One way to analyze these effects of the sector on the environment is through life cycle assessment (LCA), which considers the impacts of the entire product system. This research proposed a numerical method for the LCA of recycled concrete aggregate (RCA), related to carbon footprint, based on the procedures of NBR ISO 14040, using databases and other studies as references for modeling. This meets the need to simplify the LCA of the RCA determination process, given the complexity of material characteristics data, offering a practical alternative for academic and industrial applications. In the model, three main processes were adopted: concrete structure demolition, material transportation, and aggregate recycling; they were classified and quantified based on emissions from the use of electrical energy and the burning of fossil fuel. Thus, the LCA equation was modeled according to the final size of the aggregate and transport distances, making it possible to obtain a carbon footprint value. In the end, it was possible to conclude that the complete model was able to simplify the implementation of LCA in RCA, obtaining statistical consistency and reliability through validation with reference studies.