VAA Virginia Asphalt Fall/Winter 2022

16 FALL /WINTER 2022 △ continued from page 14 THE AWARD-WINNING US460 APPOMATTOX BYPASS construction, VDOT Lynchburg District’s Materials Division performed rut testing on the same high-binder base design from a previous design-build project. The Department was confident after the rut data returned positive. Asphalt Quality Control Manager Andre Royal mentioned how unusual the high-binder base felt under foot after compaction, saying the technician and he were concerned about walking on the mat after compaction on the first day of production. “It still felt soft underfoot, but after it cooled, it was as sturdy as can be. I loved how easy it was to achieve great density.” There were fourteen cores cut on the project from the BM-25.0D+0.8 that averaged 97.6% density in the three-inch lift sections and 96.4% density in the four-inch lift sections. The heightened field densities and high liquid content made for an excellent application, arguably much less prone to stripping than a conventional BM-25.0A base mix. The BM-25.0D+0.8 caused no significant change to production, laydown, or testing operations. The mainline pavement was paved in three lifts, with four-inch BM-25.0D+0.8, two-inch IM-19.0D and two-inch SM-12.5D. The highway section’s three bridges also impacted pavement design. VDOT specified performing full-depth removal and replacement to maintain vertical clearance in each location. This pavement structure was composed of a base layer of nine-inch 21-A stone base and seven-inch BM-25.0D+0.8. In total, there were eleven inches of asphalt in the full-depth replacement locations placed in four lifts: four-inch BM-25.0D+0.8, three-inch BM-25.0D+0.8, two-inch IM-19.0D and two-inch SM-12.5D. When Boxley personnel rode the first lift of BM-25.0D+0.8 upon completing a long pull, they were surprised. Even after