InfrastructureTesting new pavement materials

The Texas Department of Transportation has awarded a $1.12 million grant to a UT Arlington civil engineering professor to determine the durability of recycled materials for use in road construction.

As part of the project, UT Arlington is building a new accelerated pavement testing center, next to the UT Arlington Research Institute on Jack Newell Boulevard in Fort Worth just off Loop 820.

The center is scheduled to open this fall. The overall road pad at the accelerated pavement testing center could be a little bigger than a half-acre in size.

A University of Texas, Arlington release reports that Stefan Romanoschi, an associate professor in the UT Arlington Department of Civil Engineering, will lead the study focused on the strengths and weaknesses of asphalt mixes containing recycled asphalt pavement and recycled asphalt roof shingles. The research team includes representatives of the Texas Transportation Institute as well as UT Arlington graduate students.

“TxDOT is constantly searching for ways to improve or lengthen roadway life,” Romanoschi said. “Seeing how the recycled asphalt performs and how long it lasts could help TxDOT lengthen a road’s life and change the way the agency maintains roads.”

John Obr, TxDOT construction division director, said the agency is pleased to join with its transportation partners across the state to find better, more environmentally friendly ways to build roads.

“Studying the performance of recycled asphalt is just one of the many ways the agency gets behind projects and research to provide greener alternatives to conventional road building,” Obr said.

TxDOT is using recycled asphalt on an increasing number of maintenance and rehabilitation projects, Obr added.

“Depending on research results, the agency could potentially increase the recycled asphalt in road projects, saving millions of dollars for taxpayers,” he said.

J.-P. Bardet, dean of the UT Arlington College of Engineering, said the new pavement testing center is likely to attract new industry partners for University-led research.

“Businesses need to test materials before investing a great deal of money in them, and we are seeing much more private sector involvement in highway construction,” said Bardet, also a civil engineer. “This center is the perfect way for the private sector to determine which road materials work best and how long those materials will last.”

The release notes that in preparation for the TxDOT project, Romanoschi built an accelerated pavement testing machine that is about 68 feet long by 10 feet wide by 11 feet tall and weighs 60,000 pounds. The apparatus eventually will be transported to the pavement testing center.

The machine, which looks like a truck trailer car with an enclosed axle and wheels, will be placed on a section of the pavement made of recycled materials at the testing center. The tires move back and forth over a test section every six seconds to simulate stress and measure durability.

Many existing pavement testing centers depend on drivers on tracks to create stress conditions for road materials. Other centers use automated vehicles that run continuously to test durability. Romanoschi said his machine adds the advantage of portability; it can be transported to any location to test road materials.

“If someone wanted to move it to California or Utah to test pavement there on native soil, they could do that,” Romanoschi said, noting that UT Arlington researchers will have the ability to change the test beds at the accelerated pavement testing center to accommodate different partners and customers.

Romanoschi, who operated a similar testing facility at Kansas State University before joining UT Arlington in 2007, said sensors embedded in the test track will help researchers interpret the effect of the axle load on the pavement.

“The great thing about the center is that we built it, and we will operate it,” Romanoschi said. There currently are no pavement-testing centers in Texas, he said.

TxDOT’s current specifications permit the use of both recycled asphalt and recycled shingles, but there is little proof that using these materials yields a better or longer lasting road.

Romanoschi’s research is expected to yield a relatively quick evaluation of these materials and their strength or weakness and generate better ways of designing mixes containing recycled material.

The project’s findings could influence future construction of any surface affected by load. The work could apply to airport runways and taxiways, for example. Tire companies could use the research center to test and build a better tire, he said.