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|NuStar Expands Its Leadership in the Asphalt Industry with Investment in Warm-Mix Asphalt Technology|
|New Generation of Asphalt has Dramatic Environmental and Paving Quality Benefits
NuStar has begun installing systems at its asphalt terminals that will allow it to blend and supply warm-mix asphalt to its customers. Traditional hot-mix asphalt must be heated between 300 and 350 degrees as it is mixed with rock material at a hot-mix asphalt plant and then used to build or repair roads. The warm-mix technology NuStar is investing in and implementing decreases that temperature by 50 to 100 degrees. There are many benefits to this temperature decrease, including reduced emissions, reduced fuel usage to heat the asphalt, better pavement quality, and a longer paving season as you can lay warm-mix asphalt in cooler weather.
NuStar’s system will add and blend a waterless asphalt binder into
conventional asphalt at its terminals, and the binder changes the
properties of the asphalt to make it usable at the lower temperatures.
The binder, named Evotherm 3G, is marketed by
“We’re excited to offer this new product line because it is a ‘win-win’
situation in every way,” said
NuStar plans to have its systems in place and begin making the product
available in the
Energy Savings and Environmental Benefits
Because less fuel is needed to heat the asphalt, documented fuel savings for asphalt users generally range from 10 to 30 percent. The decreased heat and fuel usage also have proven air quality benefits. From a standard hot-mix plant, volatile organic compounds (VOCs) are reduced by 50 percent; nitrogen oxide (NOx) decreases by 60 to 70 percent; carbon dioxide (CO2) is reduced by 30 to 40 percent; and sulfur dioxide (SO2) is reduced by 35 percent. Research also shows that every 10 degree reduction in asphalt mix cuts the fumes in half, so the 50-100 degree reduction in warm-mix asphalt virtually eliminates fumes and odors. And, dust is reduced by 20 to 25 percent.
Based on these reductions, it is estimated that if all roadwork in the nation were to be done with warm-mix asphalt, it would be the equivalent of removing 1.5 million cars from U.S. roads.
And while asphalt is already the most recycled product in the world as the material has been reclaimed and reused in new asphalt mixes for many years, warm-mix allows for increased use of recycled asphalt pavement (RAP). That is because the properties of warm-mix interact better with the RAP and allow for higher percentages of the recycled material to be used in an asphalt mix.
While warm-mix technology was originally introduced as an initiative to
improve energy efficiency and environmental performance, testing and
early applications of the product in areas from research test tracks
throughout the world -- from California’s
For instance, pavement life is increased because the lower-mix temperature results in reduced oxidation and aging of the asphalt. Warm-mix additives improve compaction of the asphalt, which results in a more dense and stable road surface. The improved workability of warm-mix also reduces the paving limitations associated with cooler weather, which causes hot-mix asphalt to cool too rapidly and hinders proper application and compaction. So warm-mix will enable road construction and repair beyond the normal “paving season” that is typically from April through October. And, because the warm mix is not as hot to begin with, less time is required to cool the mix before a road can be opened or reopened to motorists.
Warm-mix also dramatically improves working conditions for road construction workers with the virtual elimination of smoke and fumes, and, much cooler working conditions.
“The introduction of warm-mix asphalt is an important step in our evolution as an asphalt company,” Anastasio added. “And going forward, we will continue looking for newer and better ways to serve our customers and improve our nation’s roadways.”
NuStar Energy, L.P., San Antonio