VAA Virginia Asphalt Fall/Winter 2022

14 FALL /WINTER 2022 Boxley Materials Company of Blue Ridge, Virginia, was founded in 1908 as an aggregate and ballast supplier for the booming railroad industry constructing mainline rails across the Commonwealth. Now a part of the East Region of the Summit Materials family of companies, Boxley’s bid for the project included serving as the general contractor and providing the project's asphalt pavement, stone base and paving installation services. In a 2018 interview with AsphaltPro magazine, Boxley Chief Estimator Eddie Blount remarked about the unique partnership opportunity the project provided his company. “Because it was a VDOT-designed project, the Department had a clear understanding of what they wanted as a finished project. There were plenty of opportunities to partner through the learning curve because the process was unique to our area. VDOT afforded us flexibility on executing the work and was a great partner on the project.” The Boxley team faced the challenge of managing traffic during construction by shifting vehicles to a single lane, comprising the travel lane and ten-foot shoulder. As the intermediate lift was completed, traffic was switched and the rubblization process was repeated on the passing lane and inside shoulder. Brian Peiklik, Boxley Project Manager, shared with AsphaltPro magazine that the benefit of this method “was that it gave us more room to work and made things safer for the traveling public.” Other challenges included significant undercut, underdrain removal and reinstallation and adjustment of planned traffic detours to accommodate motorists. There were also nuances of working with concrete that Boxley had not encountered before this project, particularly with line eradication. Before traffic could be switched, a Boxley subcontractor had to eradicate a thermoplastic longline from the concrete. This proved extremely hard on the teeth of the long-line pavement grinder, and consequently much of the marking was removed with the cutting edge of the motor-grader. Boxley subcontracted the rubblization operation to Antigo Construction from Wisconsin. They then used a Badger Breaker truck-mounted rubblizing machine to break the existing concrete into hand-sized pieces, and a Bomag Z-grid patterned steel wheel roller to crush the materials closer to the size of a #57 with a single pass. Their roller pattern included two more passes with a Bomag steel wheel roller and two additional passes from a CAT pneumatic roller for a total of five passes. To achieve VDOT’s gradation specification, they adjusted the roller pattern for in-place rubblized material by depth. Paving on the newly rubblized concrete was similar to paving on a porous asphalt layer of loose aggregate. Boxley staggered the dump trucks and shuttle buggy where possible on the non-rubblized pavement, so that only the paver was on the rubblized material. Boxley had to operate differently when the entire paving train had to be placed on rubblized material. This required additional labor in front of the paver and shuttle buggy to address areas impacted by the equipment and incoming trucks. Dump-truck drivers had to be intentional about how quickly they accelerated and decelerated to limit their impact on the surface. Boxley used a Roadtec 2500A shuttle buggy and a Roadtec 190E paver for laydown operations; and on the ramps, where there were steeper grades, Boxley utilized a Propave 110RT track paver to better distribute the weight for installation. One of the project’s highlights was the use of a high-binder asphalt base design directly on the rubblized concrete. On the mainline, this was a four-inch lift of BM-25.0D+0.8 with an asphalt content of 5.2%. To ensure rutting would not occur under traffic during THE AWARD-WINNING US460 APPOMATTOX BYPASS △ continued from page 13 continues on page 16 △