T.F. Green Airport Runway Extended Under $250M Upgrade
The extension of the main runway at T.F. Green Airport under a $250 million improvement program will allow non-stop coast-to-coast flights from Rhode Island's only commercial airport.
Cardi Corp. of Warwick, Rhode Island, has a $37.9 million contract to extend Runway 5-23 by more than 1,500 feet, bringing its total length to approximately 8,700 feet. The longer runway will enable larger, heavier aircraft to take off and land at the facility, whereas present weight limits force airlines to carry fewer passengers and less fuel with the existing 7,200-foot runway.
Safety and Efficiency
Cardi's contract is part of the T.F. Green Airport Improvement Program approved by the Federal Aviation Administration (FAA) which consists of major safety and efficiency projects. According to the Rhode Island Airport Corporation (RIAC), the safety projects are related to airfield facilities that do not meet current FAA airport design guidelines and require upgrading.
RIAC operates and maintains the state's airport system, including Green Airport and the state's five general aviation airports. Its responsibility includes design, construction, operation and maintenance of the six state-owned airports and the supervision of all civil airports, landing areas, navigation facilities, flight schools and flying clubs.
Safety projects at Green Airport entail enhancements of the Runway 16-34 Runway Safety Areas (RSA) since the RSAs on both ends of the runway do not meet current FAA design standards.
Efficiency projects identified by RIAC encompass the expansion of Runway 5-23. Moreover, FAA has confirmed the need for these facility improvements to enhance the efficiency of passenger movements. In addition, expanding the runway is said to further enhance the efficiency of the New England Regional Airport System because a runway length of 8,700 feet will meet long-term business needs.
Project Financing and Management
Work on the Green Airport Improvement began in July 2013 and is expected to continue through December 2017, according to RIAC. Financing for the $250 million program comes from federal grants, passenger facility charges and other RIAC funding sources.
The manager for the Airport Improvement Program is the Providence office of AECOM. C&S Companies of Syracuse, New York, designed the runway expansion, while Cardi Corporation was awarded the $37.9 million contract for the runway construction. Formal groundbreaking for the project took place on July 11, 2016. Cardi's work is overseen by Project Manager Robert Ferrara and Project Superintendent Robert Leone.
Scope of Work
Cardi's contract involves extending the 150-foot-wide 5-23 Runway by 1,534 feet including two 25-foot-wide paved shoulders. The Warwick contractor is responsible for the excavation and embankment for not only the extension of the runway, but also for Taxiway M, and the demolition of another, stub taxiway. Profile improvement of the 5-23 Runway is also called for. This involves milling and overlaying the existing runway to re-establish a crown and 1 to 1.5 percent cross-section down-slope for drainage.
New stormwater HDPE pipe will be installed along both sides of the runway beneath the substantial pavement structure. Stringent FAA pavement requirements call for a 26-inch-thick structure for the runway extension consisting of a 6-inch subbase blend with millings (recycled asphalt pavement, or RAP); a 6-inch crushed aggregate base course; a 10-inch bituminous base course containing 30 percent RAP; and a 4-inch bituminous surface course.
"Both the FAA and Rhode Island Airport Corporation want substantial use of recycled material to reduce demolition debris going to landfills," explained Ferrara.
Quantities of Materials
Estimated quantities of the various layers in the pavement structure are 9,825 cubic yards of the subbase course; 17,500 cubic yards of crushed aggregate base course; 26,225 tons of bituminous base course containing 20 percent maximum RAP; 19,000 tons of bituminous surface course (gradation 2, typical RW Runway) and 16,100 tons of bituminous surface course with 20 percent maximum RAP, (gradation 2, typical overlay).
Cardi forces do the actual paving, installing bituminous material from their own asphalt drum mix plant.
The contractor is milling some 88,200 square yards of pavement of variable to full depth, and is performing an estimated 263,700 cubic yards of unclassified excavation. A relatively modest amount of rock - about 1,000 cubic yards - is being excavated.
Arresting Wayward Aircraft
Cardi is also responsible for the construction of an EMASMAX Arrestor System at the end of the runway extension although the actual work will be performed by an installation subcontractor for the manufacturer, Zodiak Arresting Systems. The Arrestor System consists of a bed of blocks of lightweight, cellular cement material designed to safely stop airplanes that overshoot runways. The blocks are crushed under the weight of an aircraft, thus providing predictable, controlled deceleration. Once stopped, the material allows passengers and crew members to exit the aircraft safely and for the aircraft to be removed from the arresting system. It is FAA-accepted as an equivalent to a standard Runway End Safety Area (RESA) and is an acceptable alternative for preventing overrun catastrophes at airports where RESAs do not exist or are impractical due to environmental or other issues.
Approximately 4,500 blocks, measuring 4 feet by 4 feet and between 6 inches and 26 inches tall, will be required. The blocks form an arrestor bed measuring 417 feet by 154 feet. They will be placed over pavement previously installed by Cardi at the end of the runway extension.
Like Walking on Eggs
Installation of the blocks can be likened to walking on eggs. Workers must take great care as they unload trailers of blocks, according to specifications.
The sides of the EMASMAX block are particularly vulnerable. Fork lift load guards are covered with cushioning material (foam or carpet) to help protect the EMASMAX blocks, and foot traffic atop the blocks must be minimized. Workers wear soft-soled shoes such as sneakers or flat-soled boots. At no time are vehicles allowed to drive on the EMASMAX.
Blocks less than 6 inches in height are placed into position by hand. These lower height blocks have a maximum weight of 200 pounds but because of their size require four people to lift. Blocks greater than 6 inches in height are placed into position using specially equipped forklifts. Each block is pushed into its final position as marked on the pavement grid either by hand or using a forklift with a push plate to minimize joint spaces.
Immediately prior to actually placing blocks, a hot asphalt cement (AC-20) augmented with a crack sealing additive (25 percent by volume) is applied to the area where the block will be placed. The asphalt cement, while still hot, acts as a lubricant between the block and the existing pavement so that blocks will slide easily into their final position when pushed. Workers have only 20 to 25 seconds to push a block in place before the asphalt cools and bonds the block to the pavement.
On long runway safety areas (RSAs), the system is sized for 70-knot aircraft speed. On short RSAs, the bed utilizes the space available for maximum stopping capability. An arrestor bed can reduce FAA's 1,000-foot RSA requirement to 600 feet or less. The system is crowned for drainage, and sealed with a Jet Blast Resistant coating.
A Boost for the Local Economy
The entire project will essentially be completed to allow traffic on the extended runway by mid-December 2017.
In 2015, TF Green accommodated some 3.6 million passengers. The expansion of its main runway will allow heavier aircraft to use the facility and enable non-stop flights to the west coast.
This is expected to boost the local economy, promote new job growth, and encourage tourism to the areas, according to airport and city officials.