An Arizona-based company is working with major wireless infrastructure player Crown Castle to strengthen three Southern California towers using an innovative new product.
QuakeWrap Inc. founder Mo Ehsani, professor emeritus of civil engineering at the University of Arizona, told RCR Wireless News that one of the tower hardening projects has been successfully completed.
Ehsani’s company PileMedic produces a laminate material that comes in a fabric-like roll and can be wrapped around a structure—in this case a 55-foot monopole tower.
“This whole area of using composite materials to strengthen the infrastructure is something we started about 25 years ago,” Ehsani said.
“What is unique about our new system that we used here is we have developed a technology where we can take a sheet of fabric, which is very flexible. We can now take that fabric and by putting some resin on it and applying heat and pressure to it, we can make that fabric convert into a solid sheet.”
For the two-inch-thick Crown Castle monopole, Ehsani’s firm reinforced the lower portion with rebar anchored 14-feet-deep through the tower’s foundation. Then one layer of carbon fabric was wrapped around the entire tower with a second layer on the lower portion.
That was followed with application of a layer of resin soaked glass fabric.
The most innovative part of this retrofit, Ehsani said, was the use of patented PileMedic laminates that allow for a seamless shell around the tower; the space between this reinforcing shell and the tower is filled with a non-shrink grout.
Ehsani lauded the benefits of his product noting that while this installation was taking place, the tower stayed in service.
He also pointed out advantages associated with how the material is sold and delivered to the job site.
“The contractor doesn’t really need to know ahead of time exactly what size of shell he wants to make. It’s a fine balance with this SuperLaminate. You need enough flexibility that, in the field, you can wrap it. At the same time, it has to be rigid enough that it could stand on its own.”
For more information, check out the PileMedic website here.
Crown Castle has grown from owning 609 towers in 1998 to owning some 40,000 in 2014.