Density excellence propels S.T. Wooten to third Ray Brown win
This content appears in the Summer 2025 print edition of NAPA Quarterly. Subscribe here.
BY MARCIA DOYLE
Initially, S.T. Wooten Corp.’s project at the general aviation Carteret County Beaufort Airport did not look like a promising prospect for the Ray Brown Airport Award, NAPA’s highest honor for airfield paving.
“As soon as we began paving, we saw the asphalt mat did not adhere properly to the cement-stabilized subgrade,” said Chris Croom, Quality Control and Materials Manager for S.T. Wooten’s Asphalt Division.
This led to inadequate bonding of the asphalt to the subgrade, causing slippage cracks to form within 3 feet of the unconfined edge of the mat that aligned with the longitudinal joint of the next pull.
Fortunately, the solution was at hand. Instead of applying non-tracking tack solely between the two asphalt lifts, S.T. Wooten crews also applied it on top of the subgrade within the area of slippage.
“That solved the problem. Typically, tack coats aren’t used on this type of material, but this approach prevented cracking and created a stable edge on the mat for constructing the longitudinal joint,” Croom said. “The nontracking tack gives you a better bond between the asphalt layers and truck tires don’t pick it up and take it elsewhere. You’re not having to clean up the tack tracked all over the airport or down a highway.”
RECONSTRUCTING A SECONDARY RUNWAY
The reconstruction job involved the airport’s secondary runway, which the airport authority wanted to decrease from 150 feet to 75 feet wide. S.T. Wooten crews began by removing the existing asphalt runway and then stabilizing the soil to a depth of 12 inches.
“We had several crews from all over the company working on this project, so the sequencing of work was critical.”
Tyler Watkins, Project Manager
Although the company’s asphalt crew did the primary work, its grading crew was also brought in to complete preliminary and final grading for the project.
The company sourced mix from its plant located about an hour away. This required accounting for potential delays, as there was an active road-widening project taking place along the delivery route.
Another potential schedule complication was the Big Rock Blue Marlin Tournament, which draws around 1,600 competitors into the area vying for more than $5 million in prizes. “The airport’s quite busy during the tournament, but we were able to schedule around it,” Croom said.
The project was opened to airport traffic on Oct. 15, 2024.
SOLVING FOR JOINT DENSITY
Project specifications called for a vertical joint – created with the saw-cut technique – between the cold slab and the hot mix being laid. Noting that there would be little overlap between the two, and that joint density was a critical spec, S.T. Wooten asked for a modification.
“When we’re telling our story – whether to customers or the public – it’s important to show our commitment to quality, safety and best practices.”
– Tyler Watkins, Project Manager
They requested the project engineer’s approval to use a wedge-shaped compaction device and a low-level radiant-energy joint heater. The wedge-shaped device has an angled surface that compacts the mix as it passes through, creating a smooth, finished surface with a tapered edge. Mounted to the screed, it extends below the paver’s strike-off plate.
“We proposed using the wedge device because we didn’t feel that using a vertical joint would be a good technique for making long-lasting joints,” Croom said. “With it, you’ve got a 30-degree angle so when you come back and match that joint, you’re getting some overlap. It was a better joint, and we met the specifications.”
S.T. Wooten crews coupled that with the use of a propane-powered infrared heater along the longitudinal joint to uniformly heat and soften the pavement joint.
“It created a joint that is not only less visible, but also stronger and more durable than if we had used the saw-cut method,” said Watkins.
The end-to-end heater segments, attached to the side of the paver and positioned 1 inch above the mat, are designed to uniformly heat an area up to 18 inches wide by 3 inches deep to a maximum temperature range of 200 to 300 degrees °F.
According to Croom, S.T. Wooten regularly uses the wedge compaction device on its highway work, while the joint heater is usually reserved for airport jobs, which have joint density specs.
REPEAT WINNER
This is S.T. Wooten’s third Ray Brown Award; the previous awards were on projects at the Wilmington International Airport and the Marine Corps Air Station Cherry Point.
“We evaluate projects based on the appearance of the mat surface, joints and markings, overall ride quality and consistency of the mix testing results for air voids, asphalt binder content, gradation, and mat density,” Croom said in commenting about the awardwinning projects. “It’s also essential to have good teamwork and communication between the engineer, airport authority, and also between our people.”
“These awards are part of our overall reputation, which we consider vital to our business,” added Watkins. “When we’re telling our story – whether to customers or the public – it’s important to show our commitment to quality, safety, and best practices.”
PROJECT AT A GLANCE
| CONTRACTOR | S.T. Wooten Corporation, Wilson, North Carolina |
| OWNER | Carteret County-Beaufort Airport Authority |
| PROJECT LOCATION | Michael J. Smith Field, Beaufort, North Carolina |
| EQUIPMENT | Cat AP-1055 paver with Cat screed and Cat-designed compaction device; Heat Design Equipment Infrared Asphalt Joint Heater; Cat CB-13 and Cat Combo CB-34 rollers; Roadtec SB3000 material transfer machine. |
| ASPHALT TONNAGE | 8,500 |
| MIX | P-401 mix with an optimum asphalt cement content of 5.1%. Surface mix has an aggregate top size of 100% passing the ¾-inch sieve, obtained from two different quarries. PG 76-22 binder grade; 25% anti-strip additive. |
| PROFILOGRAPH RESULTS | Average IRI of 1.86 inch/mile, with zero must-grind areas. |
