Paving America's First End-Around
|Thanks to the new end-around, planes landing on Runway 8L/26R will just travel to the end of the runway and turn onto the new 4,200-foot-long Taxiway V. The taxiway dips 30 feet below the level of the adjacent runway before emerging at the gate area, allowing planes to keep taking off from the runway without any interruptions.|
At Atlanta's Hartsfield-Jackson International Airport, work has recently been completed on a project that's the first of its kind at an American airport. It's called an end-around, and there is only one other like it (in Frankfurt, Germany).
Taxiway Victor (V) is the nation's first Federal Aviation Administration (FAA)-approved end-around taxiway. Before Taxiway V opened, the approximately 700 airplanes a day that landed on the airport's northernmost runway (Runway 8L/26R) had to wait in line for clearance to taxi across the other active runway, Runway 8R/26L, to get to taxiways Echo and Foxtrot or to the terminal gates.
Now, when the planes land on Runway 8L/26R, they just travel to the end of the runway and turn onto the new 4,200-foot-long (1,280 meters) Taxiway V. The taxiway dips 30 feet (9.1 meters) below the level of the adjacent runway before emerging at the gate area. The dip in the taxiway allows planes to keep taking off from the runway without any interruptions.
FAA studies have predicted a 30-percent improvement in overall runway efficiency because of the new end-around. Airlines are hoping to save an estimated $26 million to $30 million per year, because their airplanes won't be sitting on the runway as long waiting to take off or waiting to taxi. It also means fewer delays for travelers and a safer traveling experience.
Archer Western Contractors, based out of Atlanta, won the bid for the end-around at the airport. A tight company-imposed deadline of 30 days or less to complete the 50,000 square yards of concrete paving was given for the project. To complete the project, the company used its GOMACO paving equipment. Concrete was supplied by LaFarge, and Archer Western worked closely with the concrete supplier to develop a durable mix that could stand up while being slipformed to meet the project's required flexural strengths.
"We had some problems with the initial mix design and some of the super plasticizers and other exotic ingredients in it," said Don Cowan, paving coordinator for Archer Western. "We worked together to simplify the mix but still meet the project requirements. It had to meet flexural requirements of 650 psi at 28 days. The final result was a wonderful mix design that stood up well and left a really nice finish."
Security on the airport created some delays in concrete delivery, as the trucks passed through a main check point. To compensate, more end-dump trucks were utilized, averaging 15 to 18 trucks on the project. The trucks carried 9-cubic-yard loads of concrete and dumped into a 9500 placer working in front of the GOMACO GHP-2800 two-track paver.
"For placing concrete on this project, we preferred using a 9500, because we don't have to worry about getting on the reinforcing steel or baskets or anything like that," Cowan said, adding, "It also put down concrete very fast and effectively. We've had production of 250 cubic yards an hour and that's very good, especially when you're considering traffic, working in a secured area, and other factors that can slow down production."
The end-around taxiway is 130 feet wide and 4,200 feet long. It was slipformed in four paving passes with the GHP-2800 paving 25-foot-wide, 20-inch-thick jointed concrete with 26-inch thickened edges on the slab. A Commander III slipformed 15-foot-wide shoulders over continuous steel reinforcing to complete the new taxiway.
"Both of the pavers on the project were very well suited to the kind of work they did," Cowan said. "The GHP-2800 is the right machine to do dual-lane paving, and it handled the thick concrete very well. We were working both pavers hard, and they produced a beautiful slab."
A T/C-600 texture/cure machine followed behind the pavers applying a burlap drag and light broom finish.
"It was definitely an interesting project for us," Cowan said. "It was challenging in several aspects. We were pouring on a cement-treated base and we had to watch the cure times on that. It was a relatively cut up job, and the sequencing of the work and dealing with the variable factors was challenging.
"Overall though," he added, "the project and the smoothness we achieved on it passed everyone's expectations with flying colors. I heard secondhand that the pilots are having to put on their brakes as they go around the end-around taxiway because it's so smooth." It was a successful project for the company all the way around. They beat their company-imposed deadline and finished the project in just 24 days. Concrete paving production averaged 1,200 to 1,500 cubic yards per pour.