Kubricky Construction Corp., Queensbury, NY, embarked on its first major night Superpave project armed with the right equipment.
Kubricky used a new Blaw-Knox PF-5510 paver with a Blaw-Knox MC-30 mobile conveyor to put down 130,000 tons (117,000 t) of hot mix asphalt (HMA).
In addition to the leveling course crews had a 2-in. (5 cm) thick binder and a 1.5-in. (3.8 cm) surface course. Crews also has five heavy-duty Ingersoll-Rand vibratory rollers following the paver/mobile conveyor to obtain the stringent compaction specifications.
“As for using the MC-30 mobile conveyor, I can tell you that it makes a big difference in the road’s rideability,” said Michael Speshock, project manager, Kubricky. “Last year on a job similar to this one, we were able to put through 150,000 tons of Superpave mix that had a crushed granite aggregate. We did have to replace a few wear parts but other than that, it really did a great job.
“With it there are no trucks bumping the pavers, and it helps reduce segregation in the mix. Using the MC-30 doesn’t require that we slow our production down a bit. It actually speeds it up at times like when we just start in an evening and have a line of trucks waiting. The new PF-5510 laydown machine can handle anything the MC-30 can feed it, and probably a little bit more,” said Speshock.
Before any of that could take place however, crews had to mill off about 6 in. (15 cm) of old asphalt and go .5 in. (1.27 cm) down into an existing concrete pavement. That had to be repaired and only than could crews come back and put down a 2-in. (5 cm) thick T & L asphalt course. Both the binder and surface courses of the critical Superpave PGT 64-28 mixes were then added. Now add the time requirements to the equation, and here’s where things heat up.
“Oh yes, the majority of the paving portion of the 4.8-mi. long rehabilitation and resurfacing contract had to be completed at night while maintaining traffic on a highway with an ADT of 75,000 to 83,000 vehicles. Safety was our most important product. Even though we had all the machines and materials that we needed, it was the quality of the men that I had that made the job all come together in the end,” said Speshock.
In an effort to increase safety, quality and productivity, Kubricky also had 50 self-contained portable light stands on site to comply with state nighttime lighting requirements. Of these, 43 were Ingersoll-Rand L5 models.
Situated in southern Saratoga County on I-87 at the Albany County line, the job ran north between Exit 7 and Exit 9. The three-lane road in each direction has a wide, mostly forested, median divider. The highway is a direct link to Canada on the north, and to New York City and northern New Jersey on the south. At night, when the almost constant automobile traffic was lightest, the commercial truck traffic increased significantly.
State DOT specifications required the contractor to be totally clear of the southbound portion of the highway by 6 a.m. and that there were to be no lane closures whatsoever between then and 10 a.m. The reverse was true for the north side between 3 to 7 p.m. A single lane shutdown was permitted on the north side in the mornings.
In addition to the deep asphalt milling, concrete milling, patching and resurfacing with Superpave asphalt, there was about 100,000 cu. yds. (760,000 cu m) of earthwork. This was mainly to rebuild old shoulders and to put in one 2,500-ft. (758 m) speed change lane and an extra exit lane at Exit 9.
Night was the only time period that double-lane closures, necessary to proper resurfacing practices, were permitted. And there were very heavy penalties in place for contractor noncompliance.
The initial asphalt and concrete milling was subcontracted to a Kubricky sister company, Pallette Stone Company. Crews used two large Wirtgen model 2100s, and one smaller model 600 milling machine. The contract specifications called for nighttime work to be carried out from Sunday through Thursday nights only.
In the beginning Pallette crews would mill out a half-mile section of road starting Sunday evening until the next day at 6 a.m. The following evening Kubricky crews would assess what concrete pavement repairs were needed.
Once the repairs were assessed, crews began working.
A quick setting concrete from Zimmerman trucks was used. The patch was then covered and the concrete brought up to a temperature of 150-degrees Fahrenheit. At this point, it was considered to be a safe cure. By Thursday night the repairs had been completed and the asphalt crew was positioned to put down at least one course of hot mix.
Speshock said that there was no time to spare because of the time limit restrictions placed on them. The T & L asphalt paving and compaction all had to be completed by the time the sun came up on Friday morning. Because the northbound side of the job was slightly less critical than the southbound, Speshock elected to work going north first to shake things out.
Jamie Flynn, Kubricky’s paving foreman, said that a typical pull on the inside lane using the MC-30/PF-5510 would be 4.5-mi. (7.2 km) long and include a wedge joint.
TransTech, Latham, NY, made the wedge joint device. The assembly bolted onto the screed next to the end gate. It has a 3 in. (7.6 cm) up and down adjustment with a 0.75- in. (1.9 cm) bolt. This enabled the crew to create a 1-in. (2.54 cm) step and a 1-ft. (.3 m) wedge. Every joint left open to traffic was done this way.
“The following night we made a wedge joint on the same side of the new pass as we did the night before. On the other side of the screed, the one adjacent to the previous night’s joint had a joint matching device. This was cranked up 1 in. above the existing joint, which by now had already been tack coated along with the road surface that we were paving. This forced the material together to make a joint which was then consolidated and compacted by the breakdown roller on its first pass of the evening. That also heated the joint all the way through,” said Flynn.
“To span the road we made four passes, an 18 ft., two 12-ft. passes and then a 10 ft. wide out side shoulder pass. Using our Blaw-Knox MC-30 last year on the I-87 Northway project we were able to pull 45-ft. a minute, and average 4,000 tons a day production. We did even better at times on this job,” said Speshock.
“I’ve been in this business a long time, but as far as coordination goes this has been the toughest job that I’ve ever had. It mandated close interagency, inter-company, and inter-personnel coordination and cooperation.
Everyone had to be in the communications loop at all times for this job to come off right. We had a combination of some fairly new construction equipment and some new construction technology. Everybody had to know what it was doing,” said Speshock.
To everyone’s favor, it should be pointed out that there were high-level management meetings whenever necessary. These included all concerned parties and usually were held to modify or change procedures when and wherever necessary. These meetings involved Kubricky management personnel, regional level DOT managers, regional state police officials and others.
One of the more positive results generated from these meetings was the adoption of the contractor’s suggestion regarding full-length lane paving. Rather than pulling shorter, full-width paving sections requiring many temporary joints each time the contractor finished the night’s work, Kubricky’s people suggested making a single lane pass the entire length of the job. This was proposed in order to increase paving productivity, road rideability (smoothness), and yet it would also eliminate many of the temporary, but disruptive construction joints.
Kubricky had previously worked with a firm that had designed and fabricated a wedge joint making device that attached to the end of the PF-5510 paver’s screed. It had proven successful on past Kubricky jobs and would permit the crew to make only three longitudinal joints, which were easier to meld together. The secret to this success lay in the capability of the Blaw-Knox paver and MC-30 to lay a fast smooth mat, and solid consolidation and compaction of the adjacent asphalt with the fleet of I-R rollers.
Advance Testing from Campbell Hill, NY, was the contractor hired to constantly monitor the asphalt temperatures and compaction densities as the rollers worked the mat. Owner Jim Smith also was involved in setting up the initial rolling pattern for the project.
The contractor, according to Rory Rottella, Kubricky’s general foreman on the night shift, used two Ingersoll-Rand DD-130 rollers working fairly close together (almost side by side) as breakdown machines. These were followed behind the Superpave asphalt’s “tender zone” by two more DD-130s as intermediate rollers and followed them with an I-R DD-110 as a finish roller. The DD-110 also could function as a spare main roller if one of the big DD-130s had ever gone down.
(The preceding article appears courtesy of Blaw-Knox.) CEG
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