Statewide Asphalt Co-Op Was in 3D

For the first time in two years, the VDOT-VAA Statewide Asphalt Co-op Committee met in person! The meeting, held on Thursday, December 2, was well attended, with nearly all members present. There was much discussion around the challenges associated with contract completion for the 2021 season. In addition, topics related to COVID-19, workforce, supply chain and traffic marking were discussed at length. While there are continuing concerns with issues related to the 2022 season, both VDOT and the asphalt industry are working together to overcome as many issues as possible.

In terms of changes for 2022, the most notable dealt with the use of daily maximum specific gravity (Gmm) of asphalt mixes for field density determination. While this was not a specification change but a change to VTM-22, it was a process change for VDOT and the industry. Instead of using a running average of five results that may span one or more days, the contractor will use the average Gmm calculated each day. Therefore, contractors are encouraged to run at least three rice tests per mix per day when the Method A Density Determination approach is used on a route. Based on average plant production rates, those tests should correspond with each AC content and gradation sample retrieved in a sublot for acceptance testing.

The second change for 2022 is a specification adjustment for SM-4.75 mixes. The specification sets a minimum placement temperature of 290 F regardless of whether a warm mix technology is used to produce the mix.

The packed agenda also included continuing research on BMD implementation, SMA rutting, plastics, lump-sum traffic control and Headlight (digital density and tack reporting tool). All in attendance agreed that the in-person format provided a better venue for discussion and collaboration. The next meeting is tentatively scheduled for May 5 and is intended to be in person (possibly with a virtual option for non-members).

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