Large-scale airfield pavement projects demand a level of planning, equipment capacity, and technical precision that separates specialized aviation contractors from general heavy civil operations. The rehabilitation of Stewart International Airport, located 60 miles north of New York City near Newburgh, New York, exemplifies what it takes to reconstruct major runway infrastructure while maintaining operational constraints. This $143.5 million airfield renewal, part of a broader 10-year, $500 million capital improvement plan by the Port Authority of New York and New Jersey, pushed the limits of asphalt production, placement, and quality control. The approaches taken by the joint venture of Tutor Perini Corporation and Intercounty Paving Associates offer valuable lessons for any contractor working on high-stakes pavement projects. For broader context on how international research shapes structural design and construction materials, see Innovations in Civil Engineering From International Research Conferences.
The Scope of the Stewart International Airport Airfield Renewal
Stewart International Airport operates two runways. Main Runway 9/27 stretches 11,817 feet with 35-foot-wide shoulders. Crosswind Runway 16/34 measures 6,004 feet long with the same width configuration. Together they handle commercial freight, general aviation, and international traffic. In September 2013, the airport served as the preferred entry point for world leaders attending the 68th United Nations General Assembly, highlighting its strategic importance.
Project Timeline and Phases
The rehabilitation project began in mid-2013 and was scheduled through May 2015. The work covered both runways and several adjoining taxiways, encompassing full-depth reconstruction, milling, overlays, widening of shoulders, and construction of a new high-speed turnoff. Intercounty Paving Associates took responsibility for all milling, paving, and recycled concrete aggregate operations.
Runway Closures and Production Schedules
Working within an active airport environment required carefully coordinated closures. The project used two intensive 14-day closure windows on separate runway sections:
- First closure placed 45,000 tons of asphalt in 14 days on Runway 16/34 while part of Runway 9/27 was also shut down for intersection work.
- Second closure placed 25,000 tons of asphalt over another 14-day period on the remaining sections.
Intercounty placed 130,000 tons of asphalt in 2013 and expected over 125,000 more in 2014, including material for a new taxiway. The combined total exceeded 260,000 tons by project completion. The work was part of a larger terminal expansion transforming Stewart into a more significant regional transportation hub. For builders interested in major industry events, Highlights From the International Builders Show New Products provides useful coverage of emerging construction trends.
Asphalt Mix Design and Placement for Aviation-Grade Pavements
Airfield pavements must withstand loads far beyond highway applications. Aircraft landing gear concentrates immense weight onto small tire contact areas, and jet blast, fuel spills, and high-speed turning forces place unique demands on the surface. The Stewart project used Federal Aviation Administration specification P401, the standard for airport asphalt pavements.
Mix Composition and Material Specifications
The FAA P401 mix consisted primarily of 3/8-inch stone aggregate with some half-inch material, combined with 5 percent liquid asphalt content. Key characteristics included:
- Polymer-modified hot mix asphalt for mainline runway lifts to provide additional stiffness and rut resistance under heavy loads.
- PG76-22 binder for material within 6 inches of the top of grade, delivering high-temperature performance suitable for summer operations.
- PG64-22 binder with Evotherm warm mix additive for material deeper than 6 inches from top of grade, balancing performance with workability.
- Warm mix asphalt design with Evotherm modifier for shoulder placements, reducing compaction temperatures and extending the paving season.
The mix was produced by Jointa Lime at a portable plant just off the airport site, allowing rapid delivery and consistent quality control.
Variable Depth Paving and Profile Correction
One of the most challenging aspects of the runway rehabilitation was the variable depth of the asphalt lifts. The existing runway surface had developed undulations over years of service, requiring profile correction. In 2013, crews milled one inch off the existing surface and replaced it with varying depths of polymer-modified mix to create a smooth, level grade.
Depth varied dramatically across the runway surface:
- Some areas required as little as 3 inches of additional material.
- Other sections needed up to 30 inches of fill to correct underlying grade issues.
- All areas were leveled to within 3 inches of the final grade, then topped with a uniform 3-inch surface course.
The finished pavement was designed with a 1.5 percent pitch from centerline to each edge for drainage, while shoulders sloped at up to 3 percent. These drainage considerations are critical for aviation safety, as standing water on runways creates hydroplaning risks.
Equipment Strategy: Single-Paver Approach and Fleet Modernization
The Stewart project became a catalyst for a major equipment investment and strategic shift by Intercounty Paving Associates. The decision to use a single wide-paver instead of the conventional two-paver echelon method saved labor costs, improved quality control, and reduced longitudinal joint count by half. For contractors evaluating equipment decisions, How Builders Get Most From International Builders Show offers practical advice on evaluating new equipment and technologies before major purchases.
The Vögele Super 2100-2: One Paver, One Crew, Six Passes
Frank Lizza, general manager of Intercounty Paving Associates, had an insight during a tour of Wirtgen Group manufacturing plants. While observing finished equipment in the loadout area, he saw a 40-foot solid screed and realized a 25-foot screed would let his team pave the full 150-foot runway width in six pulls with a single paver, rather than using two pavers in echelon.
After returning from the plant tour, Intercounty reviewed its bid calculations and set up a demonstration at John F. Kennedy International Airport. The demo confirmed the approach was viable, and the company acquired a Vögele Super 2100-2 with a TP2 high-density compaction screed. The advantages of this single-paver approach included:
- Elimination of half the longitudinal joints on the runway, reducing potential weak points in the pavement structure.
- Reduction in testing requirements by half, since each longitudinal joint required separate density and bond testing.
- Labor savings from operating one paver and one crew instead of two coordinated teams.
- Improved grade control, as the 25-foot screed maintained consistent pressure across its full width.
Intercounty also purchased a Vögele Vision 5200-2 tracked paver with a VF 600 front-mounted extending screed for narrower sections. While the Super 2100-2 is designed as an international-scale machine for heavy, wide lifts, the Vision series was engineered specifically for North American applications, giving the fleet flexibility for different project conditions.
Complete Conversion to an All-Wirtgen Milling Fleet
The Stewart project also drove a full replacement of Intercounty’s milling equipment. Over two years of discussions between the company and distributor Edward Ehrbar Inc. of Yonkers, New York, led to the decision to convert the entire cold mill inventory to Wirtgen machines. The fleet transitioned from a mix of brands to ten Wirtgen mills:
- Two standard W 250 models with Tier 3 emissions technology.
- Eight W 250i models with Tier 4-interim compliance for reduced emissions on a jobsite operating near active aircraft.
- Four half-lane machines and six full-lane machines to handle both narrow taxiway work and wide runway milling passes.
At peak production, five Wirtgen W 250 mills ran continuously for 17 hours to maintain the aggressive closure schedule. The mills used 18-millimeter drums running at 2,100 rpm with a slow, steady travel speed to produce a smooth surface without the deep texture marks of wider drum spacing.
Quality Control, Compaction, and Sustainability Practices
Achieving FAA-specified pavement density on an 11,800-foot runway requires careful roller train configuration, consistent material temperature management, and rigorous testing protocols. The Stewart project demonstrated how modern equipment can deliver superior compaction while reducing crew size and operating costs. Contractors looking for reference standards should review How to Access Free Building Codes Online Navigating for guidance on finding applicable specifications.
Roller Train Configuration and Density Results
The Vögele Super 2100-2 with the TP2 high-density screed achieved 86 to 88 percent compaction out of the paver, giving the roller operators a strong starting point. The compaction train used three new Hamm rollers:
| Roller Model | Role in Compaction Train | Target Density Contribution |
|---|---|---|
| Hamm HD+ 140 HF | Breakdown rolling behind the paver | Initial compaction to 92-94 percent |
| Hamm HD+ 120 HF | Intermediate rolling for density build | Mid-range compaction to 96-97 percent |
| Hamm HD+ 140 VO | Finish rolling and surface sealing | Final spec of 98 percent on mat |
The target compaction specification was 98 percent or better on the main mat and 96 percent on longitudinal joints. By achieving 86-88 percent directly out of the paver screed, the team could theoretically have used only two rollers, but maintained three for quality assurance. This conservative approach ensured consistent density across the full 25-foot width despite the stiff polymer-modified mix.
Recycled Materials and Environmental Compliance
Once the runway expansion encroached on grassy areas, the state permit required mitigation by converting existing unused concrete aprons to grassland. This created demolition concrete processed on site using a Kleemann Mobirex MR 110 ZS mobile impact crusher:
- Existing concrete infield areas were removed and the space converted to replacement grassland to satisfy environmental permit conditions.
- The demolished concrete was crushed and stockpiled as recycled concrete aggregate (RCA) for use in new taxiway and runway pavement base layers.
- Asphalt millings from the runway surface removal were reused as a 6-inch subbase material under the new runway shoulders.
Shoulder Construction Sequence
The runway shoulders required a different approach than the mainline pavement due to lower structural demands and in-place utilities. Instead of cold mills, crews used dozers and excavators for removal. The shoulder section build-up consisted of:
- 6 inches of RAP millings as a subbase layer, providing drainage and structural support.
- 4 inches of macadam plant mix using 3/4-inch stone with PG 64-22 binder as a base course.
- 3 inches of warm mix asphalt surface incorporating Evotherm additive for improved workability at lower placement temperatures.
The use of warm mix asphalt on the shoulders reduced fuel consumption at the plant, lowered emissions on site, and allowed the crew to work with a wider temperature window across varying weather conditions.
Lessons for Large-Scale Asphalt Operations
The Stewart International Airport project offers several takeaways for contractors managing large-scale pavement rehabilitation. First, the equipment investment case demonstrated that a higher upfront cost for a wide paver was justified by labor savings and quality improvements across a 260,000-ton project. Second, the all-Wirtgen milling fleet provided parts commonality and consistent operator experience across ten machines. Third, the combination of polymer-modified mixes, warm mix technology, and recycled materials showed that quality and sustainability are not competing priorities in aviation pavement work.
As Frank Lizza noted, the equipment purchased for Stewart served as training for future projects. The investment positioned Intercounty Paving to remain competitive in the specialized airfield paving market across the Northeast. The approaches used at Stewart reflect the kind of practical innovation that drives the construction sector forward.