Refinements to Superpave Volumetric Mix Design: Incremental Gains and Remaining Gaps in Mixture Performance
Loading...
Authors
Tran, Nam H.
Bairgi, Biswajit
Watson, Donald
Aschenbrener, Timothy B.
Issue Date
2025-11-04
Type
Technical Report
Language
en_US
Keywords
Asphalt , Mix Design , Performance , Superpave , Volumetric Design , Regressed Air Voids , Recycling , Balanced Mix Design , Pavement
Alternative Title
Abstract
Description
The Superpave volumetric mix design system, introduced in the early 1990s, has significantly improved the rutting resistance of asphalt pavements. However, the system has not sufficiently addressed the growing need for improved cracking resistance and long-term durability, particularly for mixtures with high proportions of reclaimed materials. In response, state departments of transportation (DOTs) have implemented several approaches to improve traditional volumetric mix design procedures. These approaches include: (1) regressed air voids to increase optimum asphalt contents, (2) increased minimum voids in mineral aggregate (VMA) requirements and/or lowered design air voids to yield higher optimum asphalt contents, (3) corrected optimum asphalt content (COAC) to account for reduced binder availability in recycled mixtures, and (4) the Superpave 5 approach to increase in-place density. This tech brief summarizes those approaches and highlights other complementary strategies, including adjustments to design gyrations, minimum asphalt content thresholds, and effective binder volume requirements. While these refinements have demonstrated measurable benefits, they reinforce the need for performance-related approaches such as Balanced Mix Design (BMD).
Citation
Tran, N. H., Bairgi, B., Watson, D., and Aschenbrener, T. (2025). Refinements to Superpave Volumetric Mix Design: Incremental Gains and Remaining Gaps in Mixture Performance. Technical Brief No. UNR–TB–25–1104, AIEI, University of Nevada, Reno