Aerospace materials for on-site building of pipes of infinite length

glass fiber on the outside. This becomes the pipe.”

After testing this manufacturing method, Ehsani had a “eureka” moment when he realized that the finished pipe could be partially slid off the mandrel, and more pipe could be added to the section of pipe remaining on the mandrel. “I thought, why don’t we just slip this off of the mandrel and continue making this pipe?” Ehsani said. “Never stop.”

Carbon fiber, resin and aerospace honeycomb are all very light materials that can be transported at a fraction of the cost of conventional prefabricated steel and concrete pipe, and Ehsani said he is looking for partners to develop an automated mobile unit to make the pipes onsite.

“Imagine having a truck with a mandrel in the back,” Ehsani said. “You start making the pipe on, say, a 20-foot mandrel, and pull off 18 feet so you have two feet left on the mandrel,” he said. “Then you just move the truck forward and drop the pipe in the ground, and keep adding pipe.”

As if virtually eliminating transportation costs, slashing manufacturing costs, and reducing environmental impact were not enough, Ehsani sees this pipe technology creating jobs and boosting local economies.

“Suppose you have a pipeline project in a developing nation,” Ehsani said. “You could ship the raw materials to the workers there and they could make this pipe in their own village. No matter what size or shape they want, all they need to do is build a mandrel and make the pipe on the spot. We would be making it with local people under our supervision.”

Closer to home, Ehsani cites the recently awarded $10.7 million contract to build the first four miles of pipe for the billion dollar Navajo-Gallup water supply project, which involves building a 280-mile pipeline to supply water to more than forty Navajo communities in New Mexico and Arizona.

“The contractor is making a 42-inch diameter pipe for four miles, which works out to $507 a foot,” Ehsani said. “Really, we could have that pipe built faster with the help of local labor and put it in place sooner, without having to wait to order it and ship it, and all of that expense.”

Ehsani said he did not really set out to turn pipeline construction on its head, but the project took on a life of its own. “We developed this originally with the intention of fixing existing pipes,” he said. “Then as we started getting into this thing I realized it could be a real game-changing breakthrough technology.”

The breakthrough did not happen overnight. In the late 1980s, Ehsani and Hamid Saadatmanesh, both of the UA department of civil engineering and engineering mechanics, pioneered research into repairing and retrofitting bridges and buildings using fiber-reinforced polymers, so the technology is well established.

“There’s a lot of history on these materials,” Ehsani said, which has enabled him to refine the pipe manufacturing process to use smaller amounts of better quality materials. “Because we’re using our materials in a smart manner, we can afford to use the higher end material,” Ehsani said.

“So instead of cheaper glass fabric, we use carbon. Instead of polyester resin, we use epoxy. Because we don’t have a solid core, we can afford to put the expensive material on the skin.”

If Ehsani’s concept for mobile pipe manufacture using lightweight components takes off, he envisions an industry freed from the shackles of heavy industrial plant. “As a business model, a company that wants to get into pipeline manufacturing with one of these mobile trucks could have a factory anywhere in the world,” he said. “You could be doing a job in Hawaii today and next week be working in Panama. You’re no longer limited by where your factory is.”

Ehsani will present a paper on his new pipe technology at the American Society of Civil Engineers Pipelines 2012 Conference, being held 19-22 August in Miami.