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The $64 million rehabilitation of a major runway at Louis Armstrong International Airport was ahead of schedule with Hurricane Katrina made landfall. The runway was usable immediately after the storm, enabling the evacuation of tens of thousands of people.
As far as Jason Guy is concerned, the primary challenge in the rehabilitation of Runway 10-28 at Louis Armstrong International Airport in New Orleans was meeting the owner's time schedule.
"Completing a job valued at more than $64 million in a six- to nine-month time frame is just a huge undertaking," said Guy, project manager for New Orleans-based Boh Bros. Construction Co.
Luckily for everyone involved, especially the victims of Hurricane Katrina, the contractor was able to exceed the owner's expectations and complete the bulk of the contract before having to pull out in the wake of the storm.
The owner required the rehabilitation to be complete by Nov. 11, in time for the busiest traveling season, which is typically accompanied by the most inclement weather. The 10-28 (the east/west runway) has the most capable instrument landing system of the airport's two runways, allowing for landings on the runway when the weather is bad, visibility is limited and the north/south runway is restricted, said Roy A. Williams, director of aviation.
Consequently, the New Orleans Aviation Board offered an early completion incentive of $1 million per month and Boh was determined to get the maximum three months.
"Our goal was to beat the deadline and we investigated every opportunity to accelerate the time frame," Guy said.
Boh was on track to complete Aug. 29 and receive a hefty portion of the incentive ($2.5 million) when it became obvious that Hurricane Katrina was headed in New Orleans' direction, Williams said.
"My team was having conversations with the Boh team and I was having conversations with Robert S. Boh about whether or not they would make it," he said. "All the big stuff was done, as well as most of the signage and lighting. With a Herculean effort, Boh may have made the deadline, but now we don't know."
Still, Williams lauds the contractor for completing enough of the project to make the airport instrumental in emergency service after the storm.
"In the aftermath of the hurricane, it quickly became apparent that, in order to maximize our evacuation opportunities, we needed to open the east/west runways," Williams said. "Tens of thousands of people were evacuated from the airport, so we did make good use of the pavement. It was serendipity. If Boh Bros. had not been ahead of schedule, we wouldn't have been able to make use of it."
The removal and reconstruction of approximately 200,000 sq. yds. of runway and connecting taxiway pavement was the primary focus of the rehabilitation.
"In three years we have spent $100 million on pavement, which represents the biggest investment ever by the airport," Williams said.
The rehabilitation also included construction of a 380-ft.-long bridge and pile-supported approach slab system, replacement of a canal culvert system, enclosure of another and various flood-related infield drainage and filling.
Other than the fast-paced schedule, the biggest challenge in the rehabilitation was marrying the multi-level surfaces (which resulted from years of temporary fixes and ground settling) into a consistent surface that would meet FAA safety standards.
Safety is a constant consideration at an airport and the pavement requirements are more stringent than for any other kind of paved surface, Williams said.
"When there is a broken chunk on a highway, the worst safety risk is that a piece might fly up and hit a windshield," he added. "In an airplane, the risk is much greater because jet engines suck in an immense column of stuff at very high speed. A piece of pavement can cause an engine to explode and potentially cause a plane to crash."
Boh received a conditional mobilization for Feb. 14 and by March 14 crews had begun milling off existing asphalt, removing existing concrete where it would conflict with the new, subgraded concrete and removing sections to make way for new drainage crossings.
"There were different thicknesses in many areas, especially on the taxiways, which had been overlaid with asphalt to adjust for differential settlement over the years," Guy said. Depending upon the area and use, surfaces were milled partially or to full depth. Expanded polystyrene blocks were placed in some areas and Boh's asphalt division placed asphalt leveling and a new bond-breaker course in other areas.
"Because of the irregularities of the sub-base, they wanted a 2-in. bond breaker under the whole runway - 2 in. of asphalt, then 16 in. of concrete on top - to make it uniform and allow the concrete to slide, expand and contract," said Wayne Ponthieux, superintendent for Boh.
In order to meet FAA standards, Boh had to achieve a 700 flexural strength concrete mix, Guy said.
"We had one design for formed paving, one for slipform, and also had a pumpable mix which we could run through trucks or apply by hand in small areas, but all the mixes had to achieve the same flexural strengths."
Boh hired Beta Testing and Inspection LLC of Gretna to perform the contractor's quality control. Boh also purchased a new CMI 6000 paver that enabled crews to pour 37.5 ft. wide and 16 in. thick.
"We bought it especially for this project because the joint pattern lent itself to pouring two bays at a time," Guy said. "We needed a larger machine that could handle that."
Baker Concrete set up a central mix plant near the site and delivered concrete to various areas of the project via dump truck. "They used two bell placers as well as a placer/spreader and we used several different types of paving equipment," Guy said. "We used a Miller formless, Clary screed and CMI 3002 slipform paver, as well as the CMI 6000."
Generally speaking, air carrier runways last about 25 years before they need rehabilitating, Williams said. Both of the airport's runways were constructed during the late 1970s when the design standards called for asphalt instead of concrete.
Additionally, the rehabilitation includes high-speed taxiways that allow pilots to gradually veer off the runway onto a taxiway instead of making a sharp 90-degree turn. Because planes can get on and off a lot faster, the taxiways allow for more traffic.
"For passengers, that means the pilot doesn't have to jam on the brakes, and it makes a smoother landing," Williams said.
A big part of the project for the contractor was installing the new runway center line lights and touchdown zone lights at the proper elevation before placing the concrete, said Danny Albert, a superintendent with Boh's pipe department.
"A lot of the work was building the new slabs in conjunction with all the new, sophisticated lighting that had to be embedded in the concrete," he said.
In July, while Boh was in the middle of the project, the FAA changed a portion of the signage and marking standards, Williams said. "We had to change all of that, so we are one of the first in the country to have the latest standards."
At peak construction, Boh had between 160-170 people working and the paving department had two crews working round-the-clock for the duration of the project. Flooding was not a problem at the airport as it was in much of the greater New Orleans area, so the newly-paved runway received a welcome christening into emergency service.
In 2003, Boh completed the rehabilitation of the north/south runway and has already moved crews back to the airport to handle a changeorder for widening of one of the taxiways and future expansion of one of the concourses, Guy said.
By Sept. 16, the airport had re-started some of its passenger flight service, but there's no telling how long it will be before things return to normal.
"Our schedule was 174 passenger flights per day," Williams said. "It's hard to say when we will be back to that because so much of New Orleans' air traffic is driven by the convention and hospitality industry."
Still, the pavement is ready to receive traffic.
"A job like this is not pretty like a new parking garage or terminal. It's just nuts and bolts," Williams said. "But it's pretty important nuts and bolts."
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