Putting the finishing touches on new asphalt
Paving contractors work hard to do a perfect job, the right density, the right slope, strong joints. But what can a contractor do when a job doesn't come out as perfect as the paver-or the customer-would like?
One of the newest solutions involves infrared repair equipment, which can be used to fix even newly paved surfaces without wasting new hot mix and without creating joints in the new pavement.
"We're getting more and more calls all the time from paving contractors and other people in this business who have been recognizing that this is the way to go,"says Wes VanVelsor, president, Ray-Tech Infrared.
VanVelsor tells of a recent paving job that used Ray-Tech's mini-TMV unit with a 2-ton reclaimer box and pavement heater on the rear to improve drainage and enable the town of Charlestown, NH, to accept the finished road.
The road was in a new eight-house development. VanVelsor says there was a problem in the initial grading of the project, when the back fill material around the storm drains wasn't compacted enough. Over time the material settled around the storm drain, and as it did the asphalt pavement went with it.
"After about 18 months when the asphalt pavement settled around the drains and other areas they realized they had paved a little flat, "VanVelsor says. "There was some pooling in other areas and there were low spots on either side of every storm drain, nine of them, with 1/2 in to 3/8 inches of standing water around the drains."
The town refused to accept the road because of the standing water, and the contractor began looking for ways to solve the drainage problem.
"This was an ideal job for infrared repair because the process gives you a good bond," VanVelsor says. "The last place you want to have a joint is around a manhole or a drain because a joint just lets more water in. Infrared can fix the job without making any cuts in the pavement while creating a thermal bond with the existing pavement."
In the past contractors would have tried to correct the drainage problem with a skin patch, but the contractor determined a skin patch wouldn't hold.
"Plus, having skin patches all over the newly paved area wouldn't look good, so the town wouldn't accept a skin patch, "VanVelsor says. "Another approach they considered was to cut the low areas out and reconstruct them, but then you would have joints all the way around each drain, around the edge of the patch, which would enable water to get in and create more of a problem."
VanVelsor says the paving contractor and the city turned to infrared contractor Environmental Enterprises, Charlestown, to fix the pavement, and infrared was successful.
"We heated the pavement about 1 1/2 inches deep so it was workable, scarified the area with an asphalt rake, added some material from the reclaimer box, raked and luted it to the proper height, and then compacted it with a 1 1/2 ton vibratory roller," VanVelsor says. "It eliminated the problem."
He said that relative to other repair approaches, the infrared repair was quicker and required the least physical effort.
"Normally it takes about seven minutes or so to heat the pavement to 1 1/2 inches deep, but because this was relatively new asphalt the unit was able to heat it that deep in only five minutes," VanVelsor says.
Once the area was heated the crew used a rake to "picture frame" straight edges within the heated area at least 6 inches in from the edge of the heated area because it provides a "hot shoulder" to work to.
"If you don't do that you'll have a cold shoulder which leads to ravelling," he says. "So we rake it and add any necessary material from the reclaimer, in this case 3/8-inch mix."