On the road again! An economic and environmental break-even and hotspot analysis of reclaimed asphalt pavement and rejuvenators

Abstract

Using reclaimed asphalt pavement (RAP) can help the asphalt industry to lessen its environmental and economic impact. Although literature shows that rejuvenators are needed for high RAP rates, limited information is known about the economic and environmental impact of rejuvenators. The first objective of this research was to determine the relative service life (SL) to break even economically and environmentally when using RAP and rejuvenators. If 40% asphalt binder replacement (ABR) is considered as the benchmark for surface layers, the SL without recycling should be 27% longer to result in economic and environmental benefits. Adding a rejuvenator to 40% ABR has a limited effect on the economic impact. Conversely, when adding a rejuvenator to the benchmark, the SL should increase by 9% (SMA 10 mix) or 21% (AC 10 mix) to environmentally break even. If 70% ABR is the benchmark for base layers, the SL with no RAP should be 66% longer to yield the same economic and environmental impact. Adding rejuvenators to 70% ABR requires a 13% extension in SL to environmentally break even with the benchmark. The second objective was to identify the main contributors to the economic and environmental impact to streamline further efforts to reduce the impact of asphalt pavements. The results showed that 45% to 76% of the NPV is allocated to bitumen, plant operation, aggregates, and raw material transport. Regarding environmental impact, three processes account for 44% to 72% of the impact: bitumen, raw material transport and energy consumption during asphalt production.