Balanced Mix Design for Surface Asphalt Mixtures: 2021 and 2022 Plant Mix Schedule Pilots

Virginia Department of Transportation (VDOT) has developed two special provisions for use with Balanced Mix Design (BMD): the Special Provision for Surface Mixtures Designed Using Performance Criteria and the Special Provision for High Reclaimed Asphalt Pavement (RAP) Content Surface Mixtures Designed Using Performance Criteria. In order to begin the process of applying BMD to typical production processes, these special provisions were were inserted into several of the 2021 Plant Mix Schedules. Revised special provisions are under development for use in 2022. The objective of this project will be to document and assess the BMD plant mix schedule pilots constructed in 2021 and 2022. The assessment will address the application of the BMD concept, production variability, comparison of mixtures, differences in test responses with and without reheating of the loose mixtures for specimen fabrication, and effects of volumetric changes on the BMD test results. These ongoing pilots continue to serve as a validation for the BMD special provisions as they are applied to full-scale production. The pilots will also provide a resource to evaluate the impact of performance specifications on the long-term performance of pavement surfaces.