isotruss carbon fiber lattice structure

Opportunities open up for the adoption of lightweight composites as aging utility infrastructure needs replaced and new technologies such as 5G internet necessitate new solutions. Pictured, IsoTruss Inc. engineers lattice-shaped carbon fiber composite towers such as this for carrying telecommunications equipment. Photo Credit: IsoTruss Inc.

According to the American Society of Civil Engineers’ (ASCE) 2021 Infrastructure Report Card, aging electricity infrastructure and the need to adapt for extreme weather events due to climate change are driving innovation and funding to update utility infrastructure in recent years — though there is a long way still to go, based on the ASCE’s C- rating for the U.S. energy landscape. 

Utility infrastructure, including utility poles and cables, pipelines and cell phone towers, has, in the past, relied heavily on more traditional and less costly materials like wood or metals, but composites — demonstrating benefits like durability, longer lifespan, corrosion resistance — are increasingly adopted as an alternative in a variety of applications.

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Notably, in 2021, the U.S. implemented a bipartisan Infrastructure Law, announcing more than $185 billion in funding for projects spanning bridge and road repair, rail, public transit, upgrading power grids, installing electric vehicle (EV) chargers and more. In November 2022, one year into the new bill, the White House reported its milestones so far, including investment in updating power grids to transmit more clean energy and withstand extreme weather, clean water infrastructure, the launch of 2,800 new bridge repair and replacement projects, funding for more than 5,000 new clean transit and school buses and approved state plans for EV charging networks, high-speed internet deployment and water funding (review the full fact sheet here).

FRP utility poles and transmission cables

As aging wooden and metal utility poles are replaced, filament-wound or pultruded fiberglass composite poles offer a durable, corrosion-resistant alternative with a reported lifespan of up to 75 years.

firestrong composite utility pole

On display at CAMX 2022, this pultruded FRP utility pole FireStrong sleeve uses proprietary technology to enhance the pole’s ability to resist flames and self-extinguish. It also comes equipped with a health monitoring system so that inspectors can more easily decide whether the base pole needs replaced. Photo Credit: CW

An additional benefit for many poles available today is increased fire resistance through the use of fire-resistant resins, resin additives, veils or other solutions. For example, in October 2022 Creative Composites Group’s (CCG, Dayton, Ohio, U.S.) pultruded fiber-reinforced polymer (FRP) FireStrong poles won the CAMX Unsurpassed Innovation Award at CAMX 2022 in Anaheim, Calif., U.S. The pultruded FRP poles, which use CCG’s weather-resistant StormStrong pole as the inner base, feature a proprietary outer fire protection sleeve that is classified as self-extinguishing per UL94 standard with V0 rating. FireStrong poles also include self-monitoring temperature gages that, in the event of a fire, allow inspectors to see the strength level of the base pole.

Other notable examples in recent years include RS Technologies’ (Tilbury, Ontario, Canada) line of utility poles and FRP Fire Shield protective products that, first in 2019, have been shown to pass a variety of fire-resistance tests. In 2020, the company announced a new composite utility pole production facility in St. George, Utah, U.S., in response to increased demand for its utility poles in the U.S. Similarly, in 2020, Technical Fibre Products (TFP Burneside, U.K.) announced that its Tecnofire line of intumescent nonwoven materials, which provide fire protection for a variety of applications, are now being used for fire-resistant composite utility poles manufactured by Valmont Industries Inc. (Omaha, Neb., U.S.). 

In addition to utility poles, composites are increasingly used in electrical and other utility cables as well — specifically, pultruded carbon fiber composites as the conductive core, enabling the transmission of electricity through the cable. Carbon fiber is said to increase the capacity of electric lines as well as decreasing energy losses and sag of the wires due to overheating.

Over the past two decades, a number of companies now offer solutions in this field, such as TS Conductor (Huntington Beach, Calif., U.S.). In August 2022, the company announced the creation of a new $100 million joint venture with an energy-focused investment firm, aiming to refurbish existing electric infrastructure with TS Conductors’ products.

Among its product offerings, Exel Composites (Mäntyharju, Finland) also offers continuous pultruded conductor cores many kilometers long. In France, pultrusion and pullwinding specialist Epsilon Composite (Gaillan, France) markets a range of products, including 100% carbon fiber conductor cores, hybrid glass-carbon cores and cores with integrated functionality like a protective outer coating or embedded fiber optics. 


Utility towers, towers and protective structures

Beyond poles, composites can be used in utility infrastructure applications such as radomes, cell phone or other utility towers, and protective structures like trench and manhole covers or outbuildings.

composite building for protecting utility infrastructure

DuraFiber buildings are laid up, cured and outfitted with electrical panel boards, load centers and transformers, plus a variety of HVAC equipment, so that on-site installation labor and time are minimized. Photo Credit: Orenco Composites

In 2022 CW published a report on Orenco Composites’ (Roseburg, Ore., U.S.) DuraFiber one- or two-piece buildings, manufactured via vacuum infusion from glass fiber-reinforced polymer (GFRP) and foam core and used as outbuildings to protect power distribution centers, communication equipment and more. In this case, the GFRP provides benefits of light weight, anti-corrosion and easy installation.

For utilities that run underground like pipes and sewers, composites have been used to build or repair utility tunnel walls. QuakeWrap (Tucson, Ariz., U.S.) is one company that has demonstrated the application of carbon or glass fiber fabrics to repair and strengthen tunnels with minimal installation time. In 2019, the company published a report detailing the use of QuakeWrap products in an emergency repair to a utility tunnel underneath the University of Arizona’s campus. QuakeWrap also offers products for remote repair of pipes themselves.

For communications infrastructure, IsoTruss Inc. (Springville, Utah, U.S.) engineers customized, carbon fiber-reinforced polymer (CFRP) lattice-shaped towers for holding and protecting antennas and other equipment. In 2022, CW reported on a custom IsoTruss tower designed and delivered to the Wyoming Bureau of Land Management, which replaced a hinged metal tower that kept repeatedly breaking at the hinge points in times of snow and ice or high winds. The 40-foot IsoTruss tower, weighing only 250 pounds, provided a lightweight, anti-corrosive solution that is also, per its lattice design, suited for surviving harsh weather.

composite covers for water facility

The old concrete and asbestos covers, on the right, were subject to breakage and costly to maintain. It’s expected that the composite covers, in the blue on the left, will have a longer life and require less maintenance. Photo Credit: Soling

To protect water infrastructure, composites fabricator Soling (La Estrella, Colombia) used resin transfer molding (RTM) to build composite domes to protect a massive concrete water storage facility in Bogotá, Colombia. Also within this market, in 2021 FCI-Marbocote (São Paulo, Brazil), a company that specializes in the manufacture of mold release agents and anti-corrosion products, launched its own coating for tanks that store drinking water. Named Ycon CS Acqua, the product was developed at the request of Vantare, a manufacturer of modular composite tanks.


Corrosion-resistant pipes and water purification

Composites can also play an important role in refurbishing aging underground potable water infrastructure by providing corrosion-resistant, durable and long-lasting underground pipe solutions. 

Filament-wound fiberglass/polyester composites have also found broad application in several stages of seawater reverse osmosis (SWRO) desalination. For example, in the U.S. state of California, SWRO plants using fiberglass/epoxy pressure vessels offer one solution to the state’s growing water shortage problems. Composite pressure vessels are also used in wastewater treatment facilities to purify water for re-use.

In future, the opportunities for wider adoption of composites in these applications is almost certain to expand as pressures mount to replace aging infrastructure with longer-lasting solutions.

Landscape Photo Credit: Orenco Composites