Finishing Up the Fifth Runway

$61.8 Million Concrete-Paving Contract is Final Piece of $1.3 Billion Effort

Lane Construction Co. will have roughly one year to place approximately 450,000 sq. yds. of concrete for the much-anticipated new Fifth Runway at Hartsfield-Jackson Atlanta International Airport.

By Scott Judy

"The icing on the cake." That's what Dwight Pullen, director of the Runway 10-28 project at Hartsfield-Jackson Atlanta International Airport, calls Lane Construction Co.'s $61.8 million concrete paving contract that will finally realize the airport's long-awaited, 9000-ft.-long Fifth Runway.

Pullen's comment is as much a statement about the extreme efforts the airport has had to undertake to simply get to this point - including a $360 million excavation contract and a $160 million bridge structure contract that extends over Interstate 285 and forms the end of the new 10/28 runway - as much as it is a commentary on how he and the rest of the team sees the final piece of this $1.3 billion runway puzzle finally coming together.

"We're all pretty excited about it," said Kathy Masters, senior project manager with the City of Atlanta Department of Aviation. "It's kind of hard to believe we're there already."

The Federal Aviation Administration is scheduled to commission the new runway in May.

Straightforward, Not Simple

Lane's start to the job has been positive to date and is a main reason for the team's widespread optimism. And while Pullen and others may regard this latest contract as the least complicated of all the runway-related projects, no $61.8 million contract is ever simple.

The contractor's notice to proceed date was March 2, 2005, and it has roughly 13 months to place the approximately 221,300 cu. yds. of 20-in-thick pavement for the 150-ft.-wide runway. If Lane doesn't complete its work by that date, it faces liquidated damages of $20,000 per day. There are no incentives for early completion.

Jim Ward, paving superintendent for Lane, said the contractor plans to meet this schedule by placing an average of 3,000 cu. yds. of concrete per day of paving, and hopes to be able to construct as much as 4,000 cu. yds. in a single day.

And while the Department of Aviation was pleased by Lane's start, wet weather has proven to be a concern.

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"The weather's been a little bit of a hinderance," Pullen said. "If we can get through the weather, we think it's going to be a good contract."

Ward added that the biggest challenge the contractor faces is the "adverse weather."

Lane was using a CMI paver set at a 25-ft. width and a CMI placer/spreader supplying the concrete to the front of the paver. Dowel baskets are being used as the runway pavement's reinforcing. The pavement will sit atop a 9-in. layer of soil cement and a 24-in. subbase under that. The concrete mix is being delivered via dump trucks from an on-site batch plant. It is being designed to achieve a 650-psi flexural strength within 28 days, Ward said.

The Department of Aviation is experimenting somewhat with the inclusion of a lithium nitrate additive to the otherwise standard concrete mix design in an effort to improve long-term pavement performance. The lithium nitrate additive is intended to reduce or eliminate alkali/silica reactivity (ASR) problems, which can eventually lead to cracking of the pavement.

Quintin Watkins, project manager with the Department of Aviation, explained that the problem is fairly common to some airports that utilize deicing chemicals. The deicing chemicals can react with silica contained in the aggregate to create a byproduct that can cause cracking. The addition of the lithium nitrate obstructs this chemical reaction from occurring, and essentially changes it so that the byproduct is a benign gel that does not cause cracking.

"We're still trying to pinpoint the source of our problem," added Masters. "Our granite aggregate is very difficult to test for silica, and that has been an issue.

"We're kind of sticking our necks out on the runway" with the use of the lithium nitrate, Masters added.

Though the Department of Aviation has recently experimented with the lithium nitrate on a taxiway project it completed last year, the results won't be known for awhile.

"We'll know in four or five years if it's working," Masters said, explaining that a runway the department replaced six years ago recently started showing microscopic signs of ASR.

Actually, lithium nitrate has been used for numerous years. Masters indicated that there is roughly 25 years of performance data on the concrete admixture. She added that it hasn't been used very extensively until recently due to its high costs. Lately the price has decreased significantly, so that it is now cost-effective to consider.

"My understanding is the price point is coming down and it's a lot more affordable," Masters said.

The runway is being built to the same measurements as the airport's other landing runway, which Masters said is where the facility has mostly experienced flight delays. Though it will likely mostly be used as a landing runway - takeoff runways are longer - the flight control staff will be able to utilize it as it deems necessary.

Contractor Performance

Of course, another reason the aviation team is pleased with Lane stems from the contractor's bid.

Pullen said the department's pre-bid estimate for the project was around $70 million. The owner was pleased when the low bid came in at $61.8 million, about 5-10 percent lower than the other competitors.

"They had a very competitive bid, which brings back huge savings to the airport, the city and the project," said Pullen. "But I think what enabled us to have a good, low bid is we had a good contractor, and a good set of documents, with a lot of upfront planning. So we should expect low bids."

He added that any potential paver had to be pre-qualified by the department prior to the bid process.

Though the project was still in its earlier stages, the owner was feeling positive about the contractor's performance.

"It's still early, but they've worked well with us on issues that have come up," Masters aid. "Currently we're on schedule and on budget, so I think that speaks for itself."

As for the pending finality of this entire fifth runway effort, Masters said, "Time flies when you're scrambling around constructing. I think we're going to end up with a very good product."