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. Caltrans 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 Caltrans 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: Caltrans Materials Testing Manual, 2024 Edition. Pages 15–16 of 25.