Comparative life cycle assessment of asphalt mixtures containing recycled concrete aggregate in Egypt

This paper presents a comprehensive life cycle assessment (LCA) for hot mix asphalt (HMA) and warm mix asphalts (WMAs) manufactured using two different technologies. The investigated asphalt mixtures were prepared with recycled concrete aggregates (RCAs) as a replacement for coarse natural aggregates (NAs). The OpenLCA version 1.10.3 software was utilized for modeling the processes analyzed in this study and the life cycle inputs/outputs associated with the functional unit characterized during the life cycle impact assessment phase using the TRACI v.2.1 method. The production cost analysis was then applied to compare the investigated asphalt mixtures. The results showed that the impact of the processes associated with the production of RCA is the best for all the analyzed impact categories than NA. For the asphalt mixture production, the environmental impact of WMA with Sasobit as an organic additive was lower than HMA by 5–10%, while WMA with Asphamin as a synthetic zeolite additive increased the environmental impact values by 4–43%. In terms of production cost, the HMA showed the lowest cost compared to WMA. In addition, the use of RCA as a substitution to NA yielded a slight decrease of up to 4% in the total production of the asphalt mixtures.