Smoother landing for Napa County Airport wins top North Bay project award for 2019
Built in the 1940s by the U.S. Army, Napa County Airport's concrete runways had aged and required rehabilitation. Mead & Hunt developed the engineering plan implemented by Alex Radovanovich. Project manager John Santos supervised Ghilotti Construction Company site work.
A full depth removal of concrete was needed in some areas, and the milling off of up to 2.5 inches in others. Crack-and-seat work was performed with a pneumatic roller and surface leveling, followed by layers of asphalt concrete 4 inches thick. Some areas needed an aggregate base buildup of 9-12 inches, plus 9 inches of asphalt.
Lime and cement treatments were performed 18 inches below subgrade at three runway locations. An existing shoulder was widened with an aggregate base and retrofit activities were conducted on another runway's lighting electrical system.
The final phase involved grooving runways and striping surfaces. Some 62,000 tons of asphalt concrete were used as part of the work performed by up to 50 Ghilotti employees.
Ghilotti utilized a computer design model accurate to within one-thousandths of an inch to refurbish the runways. A 3D paving machine with an optical base lineup was used to measure precise horizontal/vertical paver angles. Ghilotti GPS manager Skylar Shearer deployed the high-tech mapping technology for precision grade checking and control when placing asphalt at thicknesses of as little as a quarter inch.
The airport remained open throughout the process. Airport Manager Greg Baer said pilots report runways are smoother. “The project came in on time and within budget,” Baer said.
