Environmental Life Cycle Performance of Recycled Materials for Sustainable Slope Engineering: Fid-Bau Portal

Environmental Life Cycle Performance of Recycled Materials for Sustainable Slope Engineering

Cordi, Adam M. / Gallagher, Patricia M. / Spatari, Sabrina

We evaluate the environmental life cycle performance of the use of recycled materials for sustainable slope engineering. Crushed glass dredged material (CG-DM) blends, (in proportions of 20/80, 50/50, and 80/20, with crushed glass reported first) for embankment fill material were compared to primary fill materials for six life cycle impact assessment (LCIA) metrics: cumulative energy demand, 100-year global warming potential (GWP), and air quality indicators nitrogen oxides (NOx), sulfur dioxides (SOx), carbon dioxide (CO₂) and particulate matter (PM). Results suggest that life cycle energy, GWP, CO₂, and SOx decline with use of recycled materials for embankment fills; however, due to increased processing at the site for the CG-DM blends, particulate matter surpasses primary-fill embankments studied herein. With respect to NOx emissions, the primary fill embankment and the 80/20 CG-DM blend have about the same amount, followed by the 50/50 blend and the 20/80 blend, in descending value, respectively. Results from this work suggest that recycled content in fill materials is beneficial to reducing energy resource consumption, GWP, CO₂, SOx and NOx (except for the 80/20 blend); however, there may be increased health risks due to increased emissions of criteria pollutant particulate matter. Overall, this study demonstrates the importance of quantifying the life cycle benefits of recycled and marginal materials as an important step towards understanding the environmental tradeoffs of their increased use in construction.