A University of Arizona engineering professor may have a solution to a U.S. infrastructure problem that's growing deadlier each year. The national Gas Technology Institute (GTI) recently published a test report approving a new technology called PipeMedic that uses carbon and glass laminates to repair and replace failing gas pipelines. GTI is a nonprofit research and development organization serving the natural gas industry.

PipeMedic technology was developed by Mo Ehsani, professor emeritus of civil engineering at the University of Arizona College of Engineering, and a pioneer in the structural application of fiber-reinforced polymers, or FRPs.

Ehsani was a faculty member in the UA department of civil engineering and engineering mechanics for almost 30 years before he left in 2009 to focus on his structural engineering repair business, QuakeWrap, which he founded in 1994. His research at UA had focused on the seismic behavior of structures, and on innovative approaches to repairing and retrofitting civil structures using FRPs.

Ehsani describes PipeMedic as a "superlaminate" because it uses crisscrossing carbon fibers and layers of glass fabric that are saturated with resin, then pressurized and heat-treated to create strips about 0.025 inches thick.

"It works like a stent," Ehsani said. "We coil the laminate around what is essentially a balloon with wheels and insert it into the pipe." The area to be fixed might be 1,000 feet away from the pipe entry point, Ehsani said, which means that pipe can be treated even if it's buried under buildings or roads.

"When the balloon is at the repair area, we pump in air and the laminate unravels and presses against the pipe," he said. "After the epoxy has dried, we deflate the balloon and remove it."

The superlaminates created at Ehsani's production facility in Tucson, Ariz., are shipped in rolls hundreds of feet long, ready for insertion into leaky pipes. The main advantage of Ehsani's laminates over most current methods is that prefabrication enables them to be strength-tested and gives them rigidity. This allows the laminates to be inserted into pipes in cylindrical coil form, which is retained as the balloon presses the laminate against the inside of the pipe.