Amherst using green resurfacing technique
Pavers on North Pleasant in Amherst Friday afternoon. Purchase photo reprints »
As Amherst continues dealing with a nearly $20 million backlog in road projects, officials are trying to find both less expensive and more environmentally friendly ways to get them back in shape.
The town recently contracted with Gallagher Asphalt of Thornton, Ill., for a hot-in-place pavement recycling technique that, according to the company, is estimated to reduce, by about one-third, the energy needed to mill and resurface a roadway.
“It’s greener, or as much as a road can be green,” Town Manager John Musante said.
Department of Public Works Superintendent Guilford Mooring said the environmental benefit is that there is no need to haul asphalt to the work site and it also reduces the number of vehicles used during renovation of a road.
Asphalt often comes from a Warner Brothers plant in Sunderland or South Deerfield, but also may have to truck in from plants farther afield, such as Palmer, Mooring said.
“That means a lot of greenhouse gases,” Mooring said. “If you take the whole green stance, it does reduce it quite a bit.”
Patrick Gallagher, vice president of Gallagher Asphalt, said the reduction in the carbon footprint is a selling point.
“You’re not using trucks to bring materials, you’re not using trucks to take away material,” Gallagher said.
But towns and cities also appreciate that the work can be done in a shorter timetable and reduce traffic congestion associated with projects, he said.
Last month Gallagher began its work on Sunderland Road with the technique known as “Recycled Hot Emulsified Asphalt Treatment,” or ReHeat. It will continue projects on a portion of North Pleasant Street north of the University of Massachusetts campus, on South Pleasant Street near the Town Common and on University Drive south of Amity Street.
Town engineer Jason Skeels said two “cooker” vehicles using radiant convection heat pass over and raise the temperature of the surface to around 400 degrees before scraping up the layer of asphalt and mixing it in an attached drum.
After one pass on an existing paved roadway — even ones filled with potholes — it lays out a new surface using the same material, he said. It does this by combining it with emulsified asphalt, which is liquid asphalt mixed with water. A roller follows behind Gallagher’s machinery.
The drawback, Skeels said, is that the process can only be used on certain roads. The ones selected were where the roadway is not being widened and the existing pavement can be reused. They also have a good, stable base.
Mooring said usually when doing a road rehabilitation job, the town or its contractor has to have machines mill and reclaim the road surface, haul away the excess material and place a binder down before placing the top level of pavement trucked to the site.
Gallagher said he expects more communities in the Pioneer Valley, and perhaps even the state Department of Transportation, will try this process after visiting the work sites in Amherst.
“This is delivering a final end product that has to look good and ride well,” Gallagher said. “We like what we’re seeing on the roads so far.”
Mooring said his initial impression is that the work has been successful, but he will appraise it again in the spring. “There are questions about how it will winter over,” he said.
“The mix looks good, the mat looks good, it looks like it will work,” Mooring said.