A Mechanistic-Empirical Pavement Design user group met last week to discuss ongoing developments with AASHTOWare Pavement ME Design, according to Eric Ferrebee, ACPA’s Technical Service Director and resident pavement design expert.

Hosted by APTech, the meeting provided AASHTO and ARA with the opportunity to discuss Pavement ME design developments. In addition to the host and sponsoring organizations, the meeting also included key stakeholder groups, including FHWA, state DOTs, and industry, as well as consultants and members of academia. The event also included a Canadian user group headed by Tim Smith of the Cement Association of Canada.

One major development was the announcement that AASHTO is planning an online version of Pavement ME sometime in 2022. The web version of the highway pavement thickness design resource will be similar to the web-based pavement design portal, PavementDesigner.org co-developed and currently managed by ACPA, with support from PCA, RMC Research & Education Foundation, and the RCC Pavement Council.

The approximately 200 participants in the three-day web conference also had the opportunity to hear updates on research studies and presentations. These included:

  • Updates on various NCHRP Research Studies, which are being evaluated for inclusion into Pavement ME. Two of note, Eric says, are on the use of geosynthetics in design and the impact of underlying concrete slabs on overlay design.
  • DOTs updates on their status of implementation with Pavement ME. This is summarized in their yearly reports which can be found on the user group website.
  • Two concrete pavement-related presentations by:
    • John Becker, President of the ACPA-Pennsylvania Chapter, who gave an update on his efforts to use Pavement ME to develop maintenance schedules for PennDOT’s long-life concrete pavement designs.
    • Julie Vandenbossche, Professor at the University of Pittsburgh, who provided program training on how to design concrete overlays. This included bonded concrete overlays on asphalt and a new design tool for unbonded concrete overlays of concrete pavements.

Many states are still in the process of implementing Pavement ME.

“This can be a large effort, as many states want to calibrate the program for local performance and also build traffic and materials libraries,” Eric says. “ACPA developed a perspectives piece that supports the point that Pavement ME with national calibrations is a good place to start for concrete pavements, particularly for states that don’t have enough data to calibrate.”

ACPA’s stance has long been that Pavement ME is a better tool than AASHTO 93, and educational efforts by ACPA engineers and others are aimed at providing both the training and tech transfer to support Pavement ME as it continues to evolve.