Agenda - Public Works Committee - 01/21/2020

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underlying asphalt pavement ....................................................................................................................... 2 Figure 2. (a) State view and (b) Minneapolis-St. Paul metropolitan area view of locations of pavements surveyed for field and laboratory work ........................................................................................................ 4 Figure 3. Truck-mounted rig used to obtain cores on-site .........................................................................10 Figure 4. Configuration of the NCAT Permeameter in attempts at field permeability testing ...................11 Figure 5. Vehicle-mounted GPR used for site evaluation ...........................................................................12 Figure 6. (a) Example of core extracted from pavement for study and (b) close-up of core shows evidence of past chip seal treatments ........................................................................................................13 Figure 7. (a) Hamburg wheel tracker test machine and (b) DCT test machine used for the project research ......................................................................................................................................................14 Figure 8. (a) Asphalt permeability test and (b) TSR test rig used for the project research ........................15 Figure 9. (a) Intact core and (b) core stripped under chip seal and between asphalt lifts, recovered from city of Shoreview, MN .................................................................................................................................19 Figure 10. Map of dielectric and density data collected at Newbury Alcove site in Woodbury, MN.........21 Figure 11. Specimens for stripping study undergoing Hamburg wheel testing ..........................................26 Figure 12. Severity of stripping in chip-sealed pavements in 18 locations with maximum theoretical density and percent air voids ......................................................................................................................32 Figure 13. Comparison of stripping of cores collected from (a-b) straight portion (with chip seal) and (c- d) cul-de-sac (unsealed) of Newbury Alcove in Woodbury, MN ................................................................35 Figure 14. Possible contribution of chip seal to advanced cracking in (a) unsealed and (b) chip-sealed pavement on Blue Heron Road in Woodbury, MN .....................................................................................36