Hot mix asphalt design follows AASHTO R 35 (Superpave volumetric mix design). Design gyrations (Ndes) based on traffic level: <3M ESALs: 75 gyrations, 3-30M: 100, >30M: 125. Volumetric criteria: VMA minimum per aggregate NMAS, VFA 65-78% for high traffic, air voids 4.0% at Ndes. CDOT additional requirements: TSR ≥80% (AASHTO T 283), Hamburg wheel track ≤12.5mm at 20,000 passes for PG 76-22 mixes.
All work under this section shall comply with CDOT current standards and applicable AASHTO, ASTM, and federal requirements. The Engineer has authority to accept or reject materials and workmanship that do not conform to the specifications.
Source: CDOT Materials Testing Manual, 2024 Edition. Pages 15–16 of 25.