Paving Florida

A bonus job on I-275 requires long hours, coordination

By Mali R. Schantz-Feld

It’s the middle of the night, and the Ajax Paving Industries crew is on a roll. They are milling and repaving a 2-mile stretch from the I-275/I-75 interchange to Terra Ceia Bay in Manatee County, Florida.

Time is of the essence, especially on this road project. “This was a fast-track job chosen for a bonus,” says Gwen Norris, Project Administrator for the Florida Department of Transportation (FDOT). Ajax is allotted 100 days to complete the project but will receive a $100,000 bonus if the job is done in 75 days. Currently, the project is scheduled for completion within 65 days, even with two days lost due to Hurricane Ernesto.

This project heralded Ajax’s premier use of the Roadtec 2500 Shuttle Buggy®, a vehicle with a conveyer in the back and hopper in the front that can hold 25 tons or 1.5 loads of asphalt.

In addition to the weather, the road dictates the schedule, too. After the friction course is completed, “the surface must cure or rest for 30 days before the thermoplastic striping can be applied,” notes Norris. “That leaves 45 days to resurface a road with four and a half full lanes of interstate and shoulders. And it’s rainy season. But that’s our goal, and I think we’ll make it.”

A Grinding Process

Several steps are involved in the resurfacing process. The milling removes 2 1/4 inches of the old asphalt to provide a smooth surface. A 12-foot-wide road-milling machine grinds off the old asphalt. The old asphalt is transported to a plant and recycled. “Asphalt is the most recycled product in the world,” explains Mike Morgan, Project Manager for Ajax.

Categorized as a petroleum product, the old asphalt is reheated and melted down at the plant and mixed with new asphalt as it liquefies. “Liquid asphalt cement (AC) or binder can cost $380 per liquid ton,” says Morgan. “That’s a big savings for us.” Mixed with aggregate and AC, the material becomes asphalt.

“There are no native materials in the Tampa Bay area to make asphalt that meet the state specifications,” explains Morgan. “The aggregate here is not hard enough to meet state specs, designed to make the road last longer. As a result, 85 percent of it is imported from Nova Scotia.”

The most difficult part of the job is sequencing all the various jobs, ramp closings, and maintenance.

The rocks arrive by barge at a plant in Port Manatee at Ajax’s receiving and stockpile facility. “We rent ‘self-unloaders’ from shipping companies to transport the aggregate,” Morgan adds.

The resurfacing mix is produced using a 12D fine mix and a PG 76-22 polymer-modified mix that is rated to traffic level D, almost the highest level. “Preparing the mix is a highly technical process,” notes Morgan, who was trained as a civil engineer. “We took mix design courses in college. A lot of science is involved. The added polymer helps to prevent rutting and cracking and increases the material’s life.”

After the road is milled, cleaned, and sweeped using a broom tractor and a vacuum truck, such as the type used to clean parking lots, it is ready for the structural asphalt. At this point the road does not drain well, and FDOT specifies that traffic cannot be put on a milled surface. “So we have to mill and pave in the same night,” notes Morgan. “We can lay a smooth mat of a 12-foot-wide travel lane, plus a 4-foot shoulder at the same time.”

A friction course, another layer of asphalt, provides the finished surface. After the application of the structural asphalt layer, the friction course offers a rougher texture, so water does not pond and cars do not hydroplane.

Raised pavement markers will provide a bumpy reminder to motorists who veer into the next lane. In Florida, the rectangular markers glow white to motorists who are driving in the correct direction and appear red if they are headed into oncoming traffic.

The Night Shift

This project heralded Ajax’s premier use of the Roadtec 2500 Shuttle Buggy®, a vehicle with a conveyer in the back and hopper in the front that can hold 25 tons or 1.5 loads of asphalt. “The paver never has to stop moving to change trucks,” says Morgan. The Shuttle Buggy gives a smoother ride to the roadway since the paver continuously moves. To train the personnel properly for safety and efficiency on this equipment, a factory representative visited the site. Operating the Shuttle Buggy requires two employees — one man on the ground level, who assists in the backing up and dumping of trucks process, and the driver, who rides 12 feet high and operates the conveyer.

The Shuttle Buggy, dubbed “Jax” and adorned with the slogan “Keep-er-movin,” is one of the most expensive pieces of paving equipment Ajax Florida has ever purchased. The cost, after prepping it for the road and adding two lights, was more than $400,000. One light in the front illuminates the ground man, Cliff Schafer, and a large globe light on top keeps the Operator, James Franklin, and his surroundings out of the dark.

Ajax will receive a $100,000 bonus if the job is done in 75 days. Currently, the project is scheduled for completion within 65 days, even with two days lost due to Hurricane Ernesto.

“Not many places do as much night work as in Florida,” Morgan explains. “FDOT has a policy of trying to impact traffic as little as possible. We have to keep a minimum amount of lanes open throughout the day. Since this project was only a two-lane highway, we didn’t have much choice but to work at night.”

Usually, in the design stage, the Department must decide the best time in 24 hours to do the work. “It seems to work out well between 6 p.m. and 6 a.m.,” says Norris. The design team studies traffic counts and decides when lane closures will impact the public the least. On this project there was also a window for lane closures between 8 a.m. and 3 p.m. The 12-hour night window, 6 p.m. to 6 a.m., that Ajax utilized, was the most productive span of time to mill and pave.

Four rollers run behind the paver to provide the state-mandated amount of density. “We are required to have 3 percent of air voids to provide for contraction,” says Morgan. One man follows behind the roller with a density gauge to measure the density of the asphalt.

The project entails a large night crew — 30 truck drivers to put down 1,500 to 1,600 tons of asphalt per night, 10 men for the paving, six for the milling, six for the cleanup, two on the Shuttle Buggy, three for traffic maintenance, two quality-control techs, and three to scatter conditioning sand on the four connecting bridges so the concrete deck does not get tack coat tracked across it. All totaled, there will be 126,034 square yards to be milled, cleaned, and repaved. This is equivalent to 10,000 tons of structural asphalt at 1.5 inches and 4,000 tons of FC-5 at 0.75 inches. That, along with cantilever signs and resodding the shoulders, should keep things busy for 75 days.

Coordinating the Project

The most difficult part of the job, Morgan explains, is sequencing all the various jobs, ramp closings, and maintenance. Traffic maintenance employees set up, maintain, and remove cones, signs, and arrow boards. Constant communication is important. “Gwen and I talk at least once every day, and we have a progress meeting every Tuesday,” says Morgan. “We discuss any paperwork or other job-specific issues.”

These meetings ensure that the project keeps running smoothly, such as in the case of Hurricane Ernesto, which shut down the project for two nights. “Every day is a coordinating day,” says Norris.
FDOT and Ajax quality-control personnel keep a watchful eye on the asphalt. “We use consultants from MEHTA and Associates, consulting engineers in Orlando, for inspection of the mix,” says Norris. “Our consultant inspectors are our eyes and ears in the field.” Inspectors stay with the crew throughout the night. While the contractor is responsible for the testing and recording, FDOT performs the quality-control monitoring and testing. Verification technicians from FDOT check inside the asphalt plant, along with quality-control inspectors from Ajax.

A Team Effort

	All totaled, there will be 126,034 square yards to be milled and repaved.

Ajax also goes the extra mile to protect the highway workers from the perils of the highway by hiring two off-duty patrol officers. “Crews are working very close to drivers going 80 miles per hour, and they sometimes don’t get a lot of respect from the traveling public in work zones,” says Morgan. In-house, Ajax’s Safety Director, Julie Simon, offers a mandatory safety program for everyone, from foremen to project managers. “Julie began as Safety Director of the Ajax Florida operations two to three years ago, and it has made a big difference,” says Morgan.

When discussing the project, Morgan rattles off his appreciation for all its participants, particularly noting that the project was contingent upon the talents of Joe White, Paving Foreman, who orchestrates all trucks, rollers, and equipment; Delbert Linear, Maintenance of Traffic Foreman; Brian Pittman, Superintendent; Tom Daquanna, Construction Manager; Jim Scott, Equipment Manager; and the staff of Advanced Specialty Contractors, signage subcontractor.