The current balance mix design (BMD) practices used by state departments of transportation vary considerably. TRB provides a glossary of these terms. TRB hosted a webinar on Monday, June 10, 2024 from 2:00 PM to 3:30 PM Eastern that shared four approaches (A through D) for optimal BMD and the benefits of moving towards a performance design approach (approach D), establishing and adjusting mixture components and proportions based on performance analysis with limited or no requirements for volumetric properties. Presenters shared an industry case study with suggestions for adjusting asphalt mixtures to meet BMD specifications. Presenters also provided a supplier’s perspective on the impact of binder source on asphalt mixture mechanical performance.

This webinar was related to the 2024 TRB Annual Meeting Workshop 1059: Adjustment to Asphalt Mixtures to Meet Performance Testing Requirements and Allow Innovations.

This webinar featured research from NCHRP 20-07/Task 506: Development of a Framework for Balanced Asphalt Mixture Design.

This webinar was sponsored by TRB’s National Cooperative Highway Research Program and the Standing Technical Committee on Asphalt Materials Selection and Mix Design.

The slides are linked in the meeting materials. View the recorded webinar below.

Webinar agenda and presenters

1. Setting the stage: Approaches A to D and moving towards Approach D – Randy West, National Center for Asphalt Technology

2. Case study: Industry practices and suggestions – Tom Bennert, Rutgers University Center for Advanced Infrastructure and Transportation

3. A supplier’s perspective: Impact of binder source on mechanical performance – Anas Jamrah, Marathon Petroleum Company LP

4. Question and answer session moderated by Tim Aschenbrener, Federal Highway Administration

The first 60 minutes of the webinar were for presentations and the final 30 minutes were reserved for audience questions.

Learning Objectives

At the end of this webinar, participants can:

1. Make asphalt mixture adjustments to pass a BMD specification

2. Understand what specifications need to be adjusted when adding a mechanical mixture performance test

3. Relate the overall BMD specification to the Superpave specification

Professional Development Hours

This webinar was delivered as a scheduled – e-learning live event and is categorized within RCEP as Technical, Health and Safety.

Professional Development Hours (PDHs) earned on completion of this program were reported to the Registered Continuing Education Program (RCEP). Certificates of Completion are issued to all participants via the RCEP.net online system. Complaints about registered providers may be addressed to RCEP, 1015 15th Street, NW, 8th Fl., Washington, DC, 20005.