At work in Adirondacks, a Wirtgen 3800 CR can foam-stabilize about 10,000 feet per day.
Two Hamm HD 130 VV tandem vibratory rollers are used for initial and intermediate compaction, and a GRW 280 pneumatic roller with 30 tons of weight used for finish rolling.
Foamed asphalt from the 3800 CR allows contractor to extend season into fall.
These days nearly any project can be “environmentally sensitive,” but this work was more so, taking place within the confines of the state park, and adjacent to the ski resort town of Lake Placid, home to the U.S. Olympic Training Center and site of the 1980 Winter Olympics.
Both the 3800 CR and 2200 CR from Wirtgen are unique in the industry as they can undertake cold-in-place recycling using emulsions, foamed asphalt or cement slurry, but with a few hours work — including addition of conveyors — can be converted into full-depth, 950-hp cold milling machines.
In early June 2012, the 3800 CR was being used on its first-ever project. “This is our maiden voyage with it,” says Mike Haggerty, sales manager, Reclamation LLC, West Hurley, NY.
The larger 3800 CR will foam-stabilize about 10,000 feet per day, compared to about 6,000 feet per day with the 2200 CR it is teamed with, Haggerty says.
“The 3800’s cut is wider and the machine is very powerful, as we hook up to a 9,000-gallon asphalt trailer and a 6,000-gallon water tanker, and push both as one unit,” he notes.
Two Hamm HD 130 VV tandem vibratory rollers were used for initial and intermediate compaction, and a brand new GRW 280 pneumatic roller with 30 tons of weight was used for finish rolling.
“It’s our second season with the GRW 280; it’s a great follow-up roller,” Haggerty said. “It kneads the material together and polishes it off, providing a surface very similar to hot mix asphalt, depending on the material.”
Traffic would use the recycled surface until a HMA overlay was placed on it a few weeks later.
The specification of foamed asphalt not only permits 100% recycling of an existing road into a stabilized road base, but actually extends the limited construction season in the mountainous Adirondacks.
“They are cold-in-place recycling a depth of 4 inches with foamed asphalt,” says Mike Marshall, director recycling products, at Wirtgen America Inc. “Two percent asphalt cement is being added by mass bulk of material. In addition, a nominal 3/4-inch-size stone is being added, pre-spread on the pavement, and mix it in with the existing pavement, and stabilize both with foam. The finished structure will be 4 inches thick.”
The “add-stone” is required by New York State specs, Marshall says.
“The combination will be 85% existing materials, and 15% new,” he explains. “The add-stone acts as a leveling agent to fill dips and irregularities in the pavement, and the higher-quality virgin aggregate supplements the RAP in the pavement, making it stronger and better. It’s a winning formula that works very well for them.”
“The foamed asphalt will allow us to work late into the fall,” Haggerty says. “Plus, in Lake Placid, tourism is the No. 1 industry. Our traffic pattern is shorter, and on this very, very busy road we have very, very few complaints. The happier the public is, the happier the resident engineer and the community will be.”
With the average production rate for the 3800 CR on this project being 520 tons per hour, in-place recycling eliminated over 50 truck trips of materials per hour in this remote, mountain location.
And the 100% recycle is just another plus for Reclamation LLC and the New York State DOT.
“Here in the Adirondacks that’s very important,” Haggerty says. “The folks up here are very environmentally conscious, and they smile at our operation.”