LowEmissionAsphalt-136pg-WhitePaper-May2023

P a g e | 40 Asphalt Paving Industry Solutions The road construction industry has been searching, for years, for methods and practices to cut the amount of energy required to produce hot mix asphalt (HMA). Today, a declining fifteen percent (15%) 80 of all flexible pavement resurfacing and rebuilding is done with recycled or so-called reclaimed asphalt pavement (RAP), with variant success (Figure 20) . Here we will discuss prevailing strategies and later introduce a potential use phase gamechanger that will lead to net zero and even negative carbon road systems. Reclaimed Asphalt Pavement RAP involves adding severely aged pavement to mixes, of course, so the biggest hurdle is that these pavements simply do not last long, giving them limited advantage both in terms of time-value cost and carbon saves relative pure virgin asphalt overlays as lifecycle assessment (LCA) 81 plays a key role in EPD requirements for cradle-to-grave . Not to be confused with cradle-to-pave . Figure 20 – Recycled Asphalt (RAP) (MMt) Source: NAPA; FHWA 80 FHWA and NAPA. 81 Aurangzeb Q et al, Hybrid life cycle assessment for asphalt mixtures with high RAP content , Dept. of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 2014. 5 10 15 20 25 30 35 40 2009 2012 2015 2018 2021 City & County DOT