The Minnesota Local Road Research Board has developed new pavement preservation guidance designed specifically for local road agencies.
Pavement preservation techniques often focus on high-volume, heavily loaded pavements, but cities and counties need approaches to resealing low-volume asphalt pavements against moisture incursion, returning some flexibility to oxidized and brittle asphalt binder, and filling in minor ruts and cracks.
The following five treatments are recommended for consideration by local agencies — based on the findings of a literature search, extensive discussion with Minnesota advisors, and a survey of 87 counties and 148 cities:
- Rejuvenating sprays that can improve asphalt flexibility
- Scrub seals with fresh emulsion and fine aggregate
- Slurry seals of binder and aggregate laid in a single pass
- Thinlays that are 5/8-inch thick and address raveling, oxidation and minor cracking
- Cape seals that combine chip seal and slurry approaches.
The guidance has been incorporated into the MnDOT Pavement Preservation Manual.
- Pavement Preservation Techniques – Local Government Focused (Chapter 6 of the MnDOT Pavement Preservation Manual) (pdf)
- Treatment Selection Guidelines for Flexible Pavements (excerpt from the MnDOT Pavement Preservation Manual (pdf)
- Technical Summary (pdf)