Another First For Stephentown
by David Flint
The second phase of paving on Route 43 from Stephentown to the Massachusetts line began last Thursday with the laying down of an experimental new type of blacktop called warm mix asphalt (WMA). Stephentown was the first site in eastern New York State selected for the use of this new technology which originated in Europe. According to Peter Van Keuren, spokesman for the New York State Transportation Department (NYSDOT), the WMA process allows conventional hot mix asphalt to be produced at a reduced temperature, thereby saving fuel at the plant and reducing emissions at the plant and in the field for the workers and inspection staff.╩ The savings realized in energy can range from 10% to 50%.╩Since each ton of hot mix produced uses the equivalent of two gallons of diesel fuel to heat, reduced fuel consumption, he said, is obviously of interest.
He added that WMA also reduces the aging of asphalt in the plant, which may provide for a longer lasting pavement when compared to hot mix asphalt.╩ Van Keuren said that NYSDOT is allowing contractors to place trial sections, as here in Stephentown, in order to learn the benefits and limitations of different types of WMA technology.╩
NYSDOT has already used over 30,000 tons of WMA on State owned roads, mostly in the Syracuse area using a number of different forms of the technology. Demonstration projects have also been carried out on some county and town roads.
Francis Grant, a native of Stephentown and Paving Foreman for Callanan Industries, was in charge of the job on Route 43. Grant is aware that NYSDOT is excited about the potential for WMA as “the green thing” that will also serve to reduce the cost of highway maintenance in the State. Some have said that in the next five years NYSDOT will be using only WMA. Grant, however, is far from convinced that the technology in its present form is the wave of the future. This was his first experience with WMA, and he was not pleased with the quality of the job that was done. Grant said they used WMA in the eastbound lane but for the westbound lane and for the shoulders they used conventional asphalt. The westbound land and the shoulders are fine, he said, but the eastbound lane is not smooth, and it is slippery even though the material is open graded for a porous surface. The material, he said, is very difficult to work with. In his 30 years in road work, Grant said he has never worked with material this bad. He believes that the machinery currently being used to lay roads will need some adaptations to properly work with WMA. He believes the technology will eventually improve but if it is to be the wave of the future it will have to test out better than this.
Van Keuren said he believes the WMA in Stephentown “was placed on a day that was apparently too cold and was too far from the plant and therefore has some ride and aesthetic issues.╩ The contractor is going to address some of these issues, but it is not completely determined the extent of the repairs required.” He added that NYSDOT did use the opportunity to make test samples to test for durability and to compare the new technology with hot mix asphalt.╩ In tests from other projects he said that so far the technology appears to maintain durability.
According to the Federal Highway Administration, “The benefits of warm mix asphalt technologies to the United States in terms of energy savings and air quality improvements are promising, but these technologies need further investigation and research in order to validate their expected performance and added value.”