AKRON—Rubber-modified asphalt is a proven technology, yet many barriers remain to its acceptance, according to two speakers at the International Tire Exhibition & Conference in Akron Sept. 13-15.
Recent problems in obtaining infrastructure funding have led to lax maintenance and deterioration of the nation's roads, according to Gary Houston, vice president/general manager of VSS Emultech.
“A road is a load-bearing device for the purpose of allowing the safe and quick conveyance of people, goods and services,” he said.
“You can do everything right when you build a road, but the road will deteriorate. If we don't maintain our nation's roads, they will deteriorate faster and faster.”
The advantages of asphalt as a paving material, Houston said, are manifold. Asphalt offers waterproofing, aggregate durability and dust abatement, he said; it is non-hazardous and viscoelastic, and it offers strength as part of the road's structural system.
Adding crumb rubber to asphalt provides two major advantages, he said: It improves the engineering properties of the asphalt, and it rids the environment of waste.
“Adding GTR (ground tire rubber) to asphalt produces a complex fluid, or a colloidal system,” he said. “Understanding the rheology of the system allows the optimization of the GTR for enhanced performance characteristics.”
Yet despite the usefulness of rubber-modified asphalt in many aspects of roadbuilding, neither road construction companies nor state highway departments have much incentive to use the material, Houston said.
“There's an inadequate understanding of the material,” he said. “It will take a multifaceted approach to move GTR-modified asphalt forward.”