For the past two weeks, a massive train of connected paving machines has been scraping up asphalt on a section of Route 346 in Hawkins County, recycling the old material and putting it back down as fresh pavement.
That 7.6 mile section of road now has the distinction of being Tennessee’s first road paved with the new technology called MARS (Mobile Asphalt Recycling System).
The Ohio-based paving contractor Strawser Construction Inc. was awarded the bid and began work on Route 346 on June 24, starting in Church Hill on what is also known as North Central Avenue at the Miller Wood Road intersection.
Resurfacing one lane at a time, MARS moved north to the Carters Valley Road intersection, where Carters Valley Road to the east also becomes Route 346.
The paving system then continued working east to the Sullivan County line at the bridge over the North Fork of the Holston River, wrapping up the first phase of the project Tuesday.
Tennessee Department of Transportation spokesman Mark Nagi said the process is called hot-in-place recycling.
“It is a process where the existing asphalt is heated gradually approximately a half-inch at a time and milled in half-inch layers,” Nagi said. “A liquid asphalt product is applied to the milled material, and it is run through a mixer onsite. The blended mix is then distributed to a paving machine and placed back onto the roadway just as a standard paving operation.”
In about two weeks, after the “new” asphalt has had a chance to cure, a crew will return to install a top sealing “microsurface,” followed by permanent striping.
The Route 346 project was awarded to Strawser Construction for $1.121 million.
Nagi said companies offering standard new asphalt placement also competed for the project, but Strawser Construction beat the next lowest bidder by about $100,000.
That’s about 9 percent cheaper than the low bid for a traditional paving crew.
Ben Pope, who is a sales manager for Strawser Construction’s Tennessee-based sister company, Southeast Emulsions, said cutting 9 percent off a city, county or state’s paving budget could amount to a hefty sum.
“You’re saving in material and manpower,” Pope said. “You’re using what’s down there already, as far as materials. As for manpower, it’s basically a train, and there’s not many people on that train. The machinery does most of the work.”
Pope isn’t prepared to say a traditional paving crew couldn’t have completed the Route 346 job in the same amount of time. But one of the big selling points of MARS is that it’s a faster process.
“It puts the asphalt right back down real fast and then you run the roller over it, and you open it back up to traffic before you could with hot mix,” Pope said. “If it was hot mix, you’d have to leave it overnight before you can put traffic on it. With (MARS) you can put traffic on it in an hour or two after it’s laid. I’m afraid to say somebody (with a regular paving crew) couldn’t do that job as fast. But it (MARS) does move quite fast. If you’re walking behind it, you’ll be a mile from your car before you know it.”
Pope said he believes MARS will be the “wave of the future” because cities, counties and states don’t have enough money to pave what needs to be paved. They’re already looking to cut paving costs any way they can.
Pope added, “What’s killed the paving industry is the price of their products has gone up so much, and the revenue coming into the state hasn’t gone up, so they’ve had to scrape to keep what they’ve got. Some of the state people said if this works they definitely will be doing more of it.”
Pope is scheduled to meet with Hawkins County Highway Superintendent Lowell Bean next week to discuss, among other things, the pros and cons of using a MARS train to pave other Hawkins County roads.
Bean told the Times-News on Tuesday he’s reluctant to try the new technology until he sees how well the pavement holds up.
“If the road holds together like it’s supposed to, and it’s less expensive, that’s definitely something we’ll be looking at in the future,” Bean said. “I think a lot of people in the area are going to be keeping a close eye on the upper (east) end of Carters Valley Road. Paving has become so expensive, you’ve got to be open to any new possibilities that are going to save money.”
Bean added, “On the other hand, we can’t jump in head first and spend that much money not knowing what we’re getting, and then maybe turn around and have to pave it again. I’ll have to be convinced that it (MARS) works before I’ll commit to it.”
Strawser Construction actually subcontracted for use of the MARS machine with Kansas-based Dustrol Inc.
Dustrol’s website describes the MARS system as the “newest method of rejuvenating asphalts of up to two inches or more.”
According to the Dustrol website, “By utilizing our process you can expect less impact on the environment; reduced cost allowing more miles of roadway to be maintained; minimal impact on traffic; and a process independent of other processes, allowing a more flexible schedule.”