Reclamation and Recycling Techniques to Achieve Perpetual Pavement Characteristics
Status: Developing RFP
The objectives of this research effort are to promote sustainability and ensure adequate performance, there is a need to consider the amount of asphalt binder available from recycled asphalt materials (RAM), including reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS). The use of recycled materials is growing due to economic and environmental benefits, yet there is no accepted method to quantify or account for the effective binder content available from these materials that represents larger fractions as RAM contents increase. AASHTO guidance on the design of asphalt mixtures with RAP and/or RAS assumes that 100% of the recycled binder is available to blend with virgin binder and any additives such as recycling agents or warm mix asphalt (WMA) products. In reality, the amount of recycled binder available is somewhere between 0% availability and near 100% availability, with lower availability for heavily aged RAP or RAS binder and mixtures produced at lower temperatures. Thus, the assumption of 100% availability leads to less overall effective binder content, yielding a dry mixture with insufficient coating that may be difficult to compact and exhibit inadequate durability and cracking performance in-service. These poor-performing pavements cost agencies due to reduced life and increased maintenance expenditures. This research will demonstrate the benefits of adequately quantifying binder availability from RAM and thus provide guidelines for their efficient use.
Different methods to quantify recycled binder availability will be explored and compared in a likely forthcoming NCHRP research project (based on #1 ranking from AASHTO COMP), but demonstration of the effects of adequate quantification of recycled binder availability in the field will be needed for implementation. The objective of this research effort is to provide this collaborative demonstration by comparing laboratory and field performance of at least two mixtures each with a pair of MnROAD test sections.
- Emil Bautista, MnDOT (TL)
- Terry Beaudry, MnDOT
- Jenna Bowers, Ingevity
- Brandon Brever, MAPA
- Steve Cross, Asphalt Recycling & Reclaiming Association (ARRA)
- John Garrity, MnDOT
- Jerry Gieb, MnDOT
- Joseph Podolsky, MnDOT
- Raul Velasquez, MnDOT
- Dan Wegman, Braun Intertec
- Initial idea proposal (pdf), 4/20/2021