While most of Reid’s testing involves materials, he also tested infrared repair techniques, which led to a full-fledged program that has now been in place for five years.
“The first infrared test we did years ago was a disaster. It resulted in the worst-looking patch I’d ever seen,” Reid says. “But a few years later, another company wanted to test it and I said ‘go ahead’ and it worked out great.”
He says that while it’s not economical to use infrared technology on large-scale repairs — and infrared doesn’t solve problems such as base failures and alligatored areas where repairs need to go deeper than the top layer — the city plans up to $2 million in infrared repairs over the next two years.
“Today we do a lot of infrared repair because it just makes sense. You have more bad spots than you have bad roads, so why overlay the entire road?” he says. “When we go out and look at a road that’s one mile long, and only 5-10% is in bad shape, we try to address just that 5-10%. If we can address those particular spots, then we’ve bought ourselves five more years on that road. And then we don’t have to spend the money to pave it now.”
He says the city amped up its use of infrared patching following a major flooding in 2010 that resulted in a 15-point drop in the city’s overall pavement condition index.
“What caused our condition index to drop was delamination of the top layer. And if it’s just that top layer that’s the problem, then infrared is the perfect remedy, because the problem is just affecting the top two inches of asphalt, and the rest is fine.”
Increase in pavement preservation
He says that advances in materials and techniques, as well as the information available about them, has made it much easier to pursue pavement preservation.
“It isn’t the city and state that were intentionally slow to adopt preservation and long-term maintenance, it was the industry itself that was slow to change,” he says. “Many more companies now offer pavement preservation services, and Metro is taking advantage of this to extend the lifetime of paved surfaces.
“Adopting pavement preservation techniques doesn’t mean you aren’t going to have to pave. You have to have the mindset that if I don’t do something with these roads I’m going to have to pave them sooner.
“If we treat roads before they fall apart, we can seriously postpone the inevitability of needing to resurface them,” he says. ”If we wait until they fall apart, it’s going to cost you serious money because resurfacing a road is the most expensive process we could perform on it. I can crackseal for pennies, and I can fog seal for pennies. No one can pave for pennies.”
He says preservation and maintenance has grown in popularity not only because it’s proved to be effective in extending pavement life, but also because cities cannot afford a reconstruction-only budget.
“When you do perform pavement preservation, your money goes further and you can afford to treat more roads during each budget cycle. That’s the reality of it,” he says.
Reid’s willingness to test new materials and his emphasis on pavement preservation and pavement maintenance means good things for Nashville. Over the last two years ending June 2012, Nashville’s approach to preventative maintenance has had a positive impact on more than 210 lane miles of road including:
- 180 lane miles of paving
- 6,139 linear feet of cracksealing
- More than 6,100 linear feet of cracksealing
- 48,500 sq. ft. of infrared repair
- 32.5 lane miles of fog seal
- 69,600 sq. ft. of pavement repair
“It means we can maintain more roads — visibly improve more roads — making more constituents happy,” he says. “In the past, people would say ‘my road needs to be paved’ but the reality was the road ‘needed to be fixed.’ Taking a preservation and maintenance approach allows us to meet the needs of more people.”
And, he says, there’s less pressure to do the significantly more costly paving.
“I’m after an 18-year life cycle,” he says. “If I can get 18 years I’m a happy man whether I do it with cracksealing, infrared, fog seal, or some combination. For the money it takes me to resurface roads, I can positively affect three times as many roads with pavement preservation.”