16 SPRING/SUMMER 2023 • 3,144.94 tons of P403 (⅜ inch nominal) 30% reclaimed asphalt pavement, 75 gyrations, PG 70-22 liquid. This mix design was tested in two lots, resulting in seven samples, with 19 joint/mat cores cut. • 6,291 tons of assorted Virginia Department of Transportation (VDOT) 9.5A mix, used for scratch courses or roadways around the runway. This mix was produced and tested under VDOT specifications. Not only was this project fast-paced, but it also required rigorous quality control checks throughout the production process. Every longitudinal joint had to be saw cut and cleaned before placing the adjacent lane, and each concrete tie-in was paved parallel to the concrete surface and compacted with a special rubber tire roller. Branscome utilized a tandem paving operation to reduce the number of longitudinal joints that had to be saw cut and improve the overall joint quality and appearance. Both milling and paving were performed with UTS machine control to meet the variable grades and precise tolerances on the final elevation of +/- 0.03 feet. The quality control (QC) data demonstrated that all 12 lanes exceeded target smoothness criteria (seven inch/ mile) with an overall average reading of 0.77 inch/mile and a single maximum reading of 1.78 inch/mile. After paving was complete, the asphalt was required to cure for 30 days before being grooved and striped. Another significant challenge was related to updated contract agreements and change orders with limited deadline extensions. During the milling phase, the team encountered an unanticipated concrete subgrade beneath the runway surface that required several inches of milling to meet final grades. This required Branscome’s team to modify the milling equipment before proceeding. After completing profile milling, Branscome received a redesigned runway profile to accommodate elevation issues on the runway ILS unaccounted for in the original design. This change added over 5,000 tons of production paving to the scope of work, including a UTS-paved leveling course. The scope of paving work also expanded to include shoulders and taxiways, increasing the scope △ continued from page 15 PAVING AGAINST THE CLOCK CHAMBERS FIELD RUNWAY-NS NORFOLK
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