“Under our new specifications, the contractor who has a Pave IR system does not have to run any density profiles,” says Rand. “Our standard specification says if they have severe thermal segregation, they automatically waive their production and placement bonus payments. Now, that does not happen if they use the Pave IR bar.
“So they don’t risk automatically waiving their bonus for having segregation or failing a density profile,” says Rand. “If a contractor using the Pave IR bar has recurring severe thermal segregation, he must take corrective action. If that fails, the state may suspend operations. (Texas defines moderate segregation as temperature differences of between 25 and 50 degrees. Severe thermal segregation is for differences of more than 50 degrees.)
“If a contractor is not using the Pave-IR bar, and has severe segregation detected by an infrared temperature gun, they automatically waive bonuses,” says Rand. “They have to run a density profile, and if that fails also, the pavement is subject to removal and replacement at the engineer’s discretion. The bottom line is that if a contractor elects to use the Pave-IR system, we are confident they will do a better job so we are willing to relax some of our other specification requirements,” says Rand.
Most contractors interviewed for this article gave the Pave IR system a thumbs-up review. Inland Asphalt, based in Richland, WA, bought a system that was specified and bid into a mill-and-fill project on SR 124 near Burbank, WA.
“We would definitely use it again,” says Chuck Barnes, general superintendent for Inland. “It gave us really good measurements of how far we went. That was great. And it told us the asphalt temperature everywhere across the mat. We didn’t have to use the temperature gun and constantly shoot everything.
“We ran it with a Roadtec Shuttle Buggy,” says Barnes. “So our delivery of mix to the paver was pretty consistent. I could see where if you didn’t run a Shuttle Buggy that you would really see a lot of variations in your mat.”
Northeast Asphalt, from Greenville, WI, bought two Pave IR systems more than a year ago, even though the state does not specify the Pave IR system.
“We typically don’t keep the system on one job for the entire project,” says John Bartoszek, regional manager for Northeast Asphalt and a sister company, Payne & Dolan. “We move the systems around and use them as quality control devices, to assure us of how our pavers are operating and to make sure we’re not getting thermal segregation. It also helps us make screed adjustments on our pavers.
“The Pave IR can tell us how many times a paver stops in a day and give us our average paving speed,” says Bartoszek. “We can see how consistent the paver speed is, and therefore we can figure how many tons per hour we’re averaging in a day, without looking back through a bunch of paperwork. If you look at one of the reports you get, you will see how many feet per minute the paver is moving. If you’re making a 12-foot pass, and paving three inches deep, you can convert over and see how many tons per hour you’re paving. That gives you a good idea for planning purposes, and also tells you how efficient you are in a certain area.”
Setting the bar high
Ervin Dukatz, PhD, P.E., is vice president of Materials and Research at Mathy Construction Co., Onalaska, WI, and the company bought a Pave IR system last year. “Our purpose was two-fold,” says Dukatz. “One is that we use it as a training tool, to give the crews visual feedback on what they’re doing. The other reason is that for our high visibility jobs, the system gives us that extra edge to help us pay attention to every detail so that we can maximize our compaction and ride values.”
Dukatz lists a series of projects for which Mathy used the system: in Wisconsin, Interstates I39 and I94, highways US 2, US 53, a SMA overlay project, and US 61, a 5-year warranty project, STH 40, a WMA overlay project; in Iowa Central City Cty 13; and Th 16 and 76 in Minnesota.