UTA’s engineering department held a demonstration Tuesday of its year-old Accelerated Pavement Testing Center in an East Fort Worth industrial park. The university and the Texas Department of Transportation are working together to determine the most durable or cost-efficient asphalt mix.
Engineers can test different asphalt formulations in the lab. But at UTA’s facility, the testing is done with wheels, pavement and computer controls.
“We’re testing with real loads,” said Dr. Stefan Romanoschi, the facility’s director and designer of some of the machinery. “We have a full-size truck axle [with wheels] that goes back and forth 100,000 times over a week.”
Five to 10 years worth of wear and tear can be simulated in just a month, even though the wheels are only moving 5 mph. That accelerates testing and allows engineers to experiment with more asphalt formulas.
This research comes at a time when cities and the state are struggling to keep up with road and highway repairs.
“We all drive every day on highways and are faced with using them for many years to come,” said Khosrow Behbehani, dean of UTA’s college of engineering. “It’s important for us to figure out how to best protect this huge investment.”
Dallas officials announced last year that they needed $900 million over four years to improve streets. For a while this year, city crews were working 12 hours a day filling potholes that were worsened by the constant rain.
State transportation officials have said they are underfunded by billions of dollars. TxDOT gave the university researchers a grant of about $720,000 to test different asphalts.
UTA engineers can’t hope to eliminate potholes. But even small gains could equal giant savings.
Romanoschi, also an associate professor of civil engineering at UTA, said a 5 percent improvement in durability would save the state about $150 million in three years.
A longer-lived asphalt also has the potential to cut down on the amount of time motorists spend in construction zones.
Even if there is no gain in durability, using recycled asphalt, including old roof shingles, could lower the material costs.
The enclosed testing facility, a 68-foot-long steel and aluminum box, cost about $1 million and was funded by UTA. The state grant is paying for the physical testing that started in March 2014 and will run through the end of this summer.
The testing center is the only one of its kind in Texas. But it’s not stuck at the site across from the UTA Research Institute.
The 60,000 pounds of machinery and enclosure is mounted on wheels and could be hauled to different locations. The adjacent testing office — housing video screens monitoring the work and a computer controlling the tests — is also mobile.
The goal is to reproduce real-world conditions as closely as possible, even if that means taking it to areas with different soil or other conditions. The current work is simulating a fully loaded semi, but it can mimic a load as heavy as double the state’s legal limit. The wheels also can veer 18 inches from side-to-side to reproduce traffic conditions.
Romanoschi said results have been promising so far, but researchers won’t reach any conclusions until after the work is finished this year.
Wade Odell, research project manager with TxDOT’s Research and Technology Implementation Office, wouldn’t try to predict the results.
“That’s why they call it research,” he said. “We’re hopeful that it yields the positive results that we’re hoping for.”
©2015 The Dallas Morning News. Distributed by Tribune Content Agency, LLC.
