As a third-generation, family-owned business with headquarters just off I-88 between Albany and Binghamton, Lancaster Development has lots of experience doing pavement rehabilitation.
However, Mark Galasso, who now runs the company along with brother, Martin, Jr. (Marty), had not always been totally satisfied with the results obtained on their highway projects.
"Marty and I have high expectations," notes Mark, "and from our standpoint, we have had too much variability. We just weren't consistent with smoothness."
The 2009 project called for performing pavement rehabilitation on approximately 24 lane miles of I-88 Portland Cement Concrete (PCC) between Unadilla and Bainbridge, NY.
It included crack and seat work on the westbound lanes, followed by four lifts of Superpave HMA on the westbound lanes, and a final wearing surface on the eastbound lanes that had had three lifts completed in 2008. In total, approximately 92,000 tons of Superpave were required to complete the 2009 portion of the project.
Setting a higher smoothness target
In March 2009, the Galassos, along with equipment manager Charlie Goodwin, met with their Milton CAT representative Mike Courchaine and a project consultant from the team formed by Caterpillar Paving Products and Seatech Publications.
In that meeting, the Galasso brothers laid out the I-88 project parameters and emphasized their firm commitment to improved smoothness results as measured by the New York Department of Transportation (NYDOT) Pavement Ride Quality (PRQ) Adjustment Level 1.
The PRQ Adjustment Level 1 is a metric specification based on the International Roughness Index (IRI) and applies to projects with three or more opportunities for smoothness improvement.
On previous NYDOT projects with the Level 1 specification, Lancaster achieved IRI scores that averaged in the 0.86 - 1.10 m/km ranges and earned a small percentage of the available quality units.
During the meeting, the Lancaster management team and the consultant looked at the IRI results of multiple lift projects from across North America and discussed ways to improve their rideability scores.
Eventually, an agreement was reached to have the consulting team assist on the I-88 project and be responsible for directing the process to achieve an average IRI of less than 0.80 m/km on the westbound lanes.
Bringing back the contact ski
One of the first steps taken by Lancaster was to bring out of storage, at the request of the consultants, their 30-foot multi-articulated averaging skis. Bob Scalaro, I-88 paving superintendent, was skeptical at first.
"In the past we've used the drag ski, but there were times we had problems using them as reference for sonic sensors," Scalaro explains. "Nowadays we have standardized on the non-contact ski. They are more convenient and take less maintenance."
On the I-88 project, however, the higher degree of averaging provided by the multi-articulated contact ski would be needed to build smoothness on the patched, crack-seated PCC surface.
"The consultants taught us a lot about installing the contact ski and the grade sensor," Scalaro continues. "Probably the biggest point was making sure that the reference string was at least four inches above the body of the ski when we use a sonic grade sensor."
The entire paving crew took part in the on-the-job training on the use of averaging skis, and the grade and slope control system prior to the start of the first lift, a 25 mm truing and leveling lift. In particular, the crew learned how to check the settings in the Topcon control boxes and to conduct the performance test to verify correct tow point valve operation.
New truck exchange procedure
Another big step was changing the truck exchange procedure used by Lancaster crews. "We had been taught a long time ago that stopping the paver between trucks caused screed settlement bumps," says Scalaro. "So, what we try to do is slow the paver to a crawl, get the empty truck out of the way, and pick up the next truck on the fly."