HOUSTON, TEXAS (April 10, 2012) -- Kraton Performance Polymers, Inc. (NYSE: "KRA"), a leading global producer of styrenic block copolymers or SBCs, announces the first commercial sale and application of its highly modified asphalt (HiMA) technology in the United States.
The Oklahoma Department of Transportation (DOT) is using Kraton Polymers' HiMA technology in a two-mile rehabilitation project on Interstate 40 in Caddo County, Oklahoma. Kraton Polymers has been advised that this high-profile I-40 project is being closely studied by personnel of the Oklahoma DOT, Oklahoma Asphalt Pavement Association, and the Federal Highway Administration.
The DOT based the pavement design and HiMA binder specification on their successful rehabilitation trial at the National Center for Asphalt Technology in Opelika, AL , which began in the summer of 2009.
HiMA uses a styrene-butadiene-styrene (SBS) polymer with a low-enough viscosity that allows use in high percentages, 7 1/2 percent, while still allowing a paving mix to remain workable and compactable. Conventional polymer modifiers, when used in high percentages, result in a mix that is too viscous and hard to compact. Modification of liquid asphalt binders with polymers improves resistance to rutting, raveling and fatigue of asphalt mixes, but there is a practical limit to polymer concentration. Usually, as polymer concentration exceeds about three percent, the viscosity of the binder increases such that the mix becomes more difficult to produce in the plant and less workable for the paving crew.
"Kraton Polymers' HiMA formulation allows durable asphalt pavement with a reduced pavement thickness that lowers costs thus permitting larger resurfacing opportunities within fixed budgets," said Bob Kluttz, Senior Research Scientist, Kraton Polymers. "HiMA technology enables the installation of roads that last longer and require less maintenance," he continued.
"Our goal is to make pavements more cost-effective," said Kluttz. "The Kraton formulation allows us to add more polymer into the mixes to achieve an asphalt thickness reduction of up to 50%, which we expect will make the pavement less costly upfront," he concluded.
"I expect to see an asphalt pavement that's a lot more resilient, something that's stronger and stiffer that will last a lot longer by being rut resistant," said Stuart Gragg, project manager for Haskell Lemon Construction Co., the paving contractor. "Superpave designs, together with this highly modified asphalt cement, will help us prolong the lifespan of this pavement," he continued. "It should be more rut-resistant and should help fight fatigue cracks. If we can go from a 10- to 12-year-life span on an overlay to a 15 to 20-year life span, that will save a lot of dollars in maintenance costs," he concluded.
