Composites continue to longer service life, reduced maintenance and faster installation, driving growth in bridges, water treatment and storage systems, rebar and other concrete reinforcement. #infrastructure #multitudeofmarkets
Top left, clockwise: Composite covers for 38-million-gallon water tank in Bogotá, Colombia; Composite bridge deck over A27 highway in Netherlands; FRP tubes for desalination plant; and FRP rebar. Photo Credit: Soling, FiberCore Europe, Protec-Arisawa and Mateenbar.
Composites offer light weight, corrosion resistance, high strength and a long lifespan — qualities that make them a natural fit for infrastructure projects. Composites are being used to rehabilitate roads, bridges, water/drainage systems and seawalls, to reinforce concrete and to build resilient structures. And while use is growing, composites still comprise less than 1% by volume of structural materials used in infrastructure.
However, progress is being made. In August 2020, the U.S. Congress passed the Composite Standards Act, which will establish a design data clearinghouse to disseminate existing guidelines and standards for using composite materials in infrastructure projects. The bill will also direct the National Institute of Standards and Technology (NIST), in consultation with the National Science Foundation (NSF), to carry out a four-year pilot program to assist in assessing the feasibility of adopting composites technology. The top three barriers to composites identified in a 2017 NIST report are durability testing, design data clearinghouse and education/training. The 2020 Composite Standards Act will help to overcome the first two while the education and training could be helped by the Innovative Materials for America’s Growth and Infrastructure Newly Expanded (IMAGINE) Act, introduced in 2018. This legislation, which has yet to be passed, is aimed to support education about the benefits and properties of composites, which will help designers and engineers rethink infrastructure projects.
Aging infrastructure continues to offer a potentially huge market for composite materials. Decaying bridges and early deterioration of concrete due to corrosion and failure of steel rebar has been well documented. Conventional repairs are time consuming and disruptive, with a projected cost in the billions. Compared to the often-seen 25-year life of steel rebar-reinforced concrete, the typical 100-year life of corrosion-resistant composites offers lifecycle cost advantages, in addition to fast installation, reduced disruption and safety benefits. CW’s 2020 feature “Building bridges with composites” actually includes updates on a wide variety of infrastructure applications, from composite manhole and trench covers to FRP rebar and marine pilings.
According to a March 2021 report from the American Road & Transportation Builders Association, more than 220,000 bridges in the U.S. require action — 45,000 are structurally deficient and another 79,500 should be replaced. At the current pace, the report claims, it would take 40 years to repair the current backlog of structurally deficient bridges. The critical need for bridges that can resist corrosion and extend useful life are part of a growing awareness that composites can play a key role in for rehabilitating crumbling infrastructure.
Projects such as pedestrian bridges continue to slowly help build this case. In 2020, Composite Advantage’s (Dayton, Ohio, U.S.) FiberSPAN FRP pedestrian bridge system was chosen by the Battery Park City Authority in New York City for the West Thames pedestrian bridge, replacing a temporary structure put in place after the September 11 attacks in 2001. FiberSPAN FRP bridge decking was also used to rehabilitate two pedestrian overpasses for MARTA stations in Atlanta, Ga., replacing heavy, decaying concrete. The lightweight, zero-maintenance composite decks allowed contractors to use the original steel trusses, minimizing the repair and labor costs associated with steel upgrades. Using concrete would also have been prohibitive, because it would have taken longer to pour and caused additional disruption and downtime for the rail station.
Composite Advantage is also supplying the lightweight FiberSPAN-C cantilever system to widen bridge sidewalks. Compared to reinforced concrete panels, the prefabricated FRP panels are 80% lighter and much quicker to install, lowering costs. The material’s corrosion resistance to chemicals and water means zero maintenance for a structure that will last nearly 100 years. Installed to accommodate pedestrians and cyclists, the FRP panels can support a 10,000-pound maintenance vehicle for sidewalks that are 7-10 feet wide and a 20,000-pound ambulance for FRP sidewalks wider than 10 feet.
Composite bridge developed by Structural Composites and installed in north central Tennessee. Photo Credit: IACMI
In 2020, Structural Composites (Melbourne, Fla., U.S.) demonstrated the PPP Composite Bridge deck, which was funded by its U.S. Paycheck Protection Program (PPP) funds. This composite bridge deck for an impoverished area in rural Tennessee features the same construction that was tested and validated in a recent Missouri Department of Transportation (MODOT) study. With a 100-year design life, the PPP deck is 90% lighter than a concrete deck and will help provide access for a community in need as well as provide field data necessary to support the MODOT’s prior testing efforts and the larger goal of improved highway bridge decks. The PPP deck will also open a market for the nation’s many small rural bridges.
The Grist Mill Bridge in Hampden, Maine, was upgraded via replacement of its former bridge span with composite beams from AIT Bridges. Photo Credit: AIT Bridges
A different approach is the composite arch bridge designed by AIT Bridges (Brewer, Maine, U.S.) which uses concrete-filled composite tubes and FRP decking, which reportedly provides an affordable and superior alternative to traditional steel and concrete for small-to medium-sized bridges. In 2020, AIT delivered a 51-foot-span, 20-foot-wide bridge for a stream crossing on state road SR 203 in Duvall, Wash. Comprising 12 fiberglass composite arches, this bridge will help restore the five-foot-wide stream to its previous 20-foot width, aiding the return of fish and other wildlife to the area while meeting local road traffic requirements. AIT Bridges also manufactures composite beams for bridge rehabilitation and replacement (see image above).
Carbon fiber-reinforced polymer (CFRP) is also being used in bridges. The Stuttgart Stadtbahn bridge, installed over Germany’s A8 motorway in May 2020, is the world’s first network arch bridge that hangs entirely on CFRP tension elements called hangers. The 72 cables are produced by Carbo-Link AG (Fehraltorf, Switzerland) using carbon fiber from Teijin (Wuppertal, Germany). They were actually cheaper than the originally planned steel cables, enabling the crossing of eight freeway lanes without supporting pillars, while their cross-sectional area was only a quarter compared to the steel solution. Further, due to their light weight, the 72 CFRP tension elements could be installed without a crane by just three construction workers. Incorporation of CFRP in the 127-meter-long railway bridge also pioneers sustainability. The EMPA (Federal Material Testing and Research Institute, Switzerland) proved that CO2 emissions during the carbon fiber manufacturing are one-third of steel and energy consumption is cut by more than 50%.
FiberCore Europe (Rotterdam, Netherlands) has installed more than 1,000 composite bridges worldwide, but its applications in North America have been limited. To address this, parent company FiberCore Holdings (Rotterdam, Netherlands) signed a license agreement in 2020 with Orenco Composites (Roseburg, Ore., U.S.) for the application of FiberCore’s InfraCore technology in the U.S. This collaboration allows Orenco to apply its extensive knowledge in the engineering and production of large composite products while growing applications for the InfraCore technology. “Bridges with InfraCore Inside are distinguished by incredible adhesion throughout their structure,” says Eric Ball, senior vice president of Orenco Composites. “They require only a minimal foundation, and because they’re relatively lightweight, they’re easy to install. These bridges are sustainable, reliable, virtually maintenance-free and designed to last over 50 years.” FiberCore Europe has also licensed its technology to Sustainable Infrastructure Systems (SIS, Adelaide, Australia) and Canadian Mat Systems (CMS) and CMSI Inc., both in Edmonton, Alberta, Canada.
Photo Credit: FiberCore Europe, Strukton Civiel Noord & Oost B.V.
FiberCore Europe is also working with large infrastructure construction specialist Strukton Civiel (Utrecht, Netherlands) to offer the sustainable SUREbridge solution for Sustainable Refurbishment of Existing Bridges. The method has been developed in collaboration with 10 European countries, the U.S. and the European Commission. Hardenberg, Netherlands, is the first municipality to use the SUREbridge method to reconstruct the Toeslagweg street bridge across the Radewijkerbeek waterway. The existing construction will be strengthened by a factor of 2 to 2.5 and widened, if desired, by mounting a prefabricated InfraCore Inside composite panel on top using mortar. If desired, prestressed carbon fiber reinforcements on the bridge underside can be used in combination. This allows the bridge to last up to 50 years, with minimal maintenance. Construction time is only six weeks, and because the existing structure does not have to be demolished, the SUREbridge method saves time and traffic disruption, as well as offering significant environmental benefits. The method also saves on costs — up to 50% compared to demolition and new construction.
Photo credit: Solico Engineering B.V.
Also in the Netherlands, Solico Engineering B.V. (Oosterhout) in partnership with composites systems integrator Advantage Composite B.V. (Franeker) engineered multiple elements made from composites for the reconstruction of multiple viaducts and underpasses along the N34 provincial dual carriageway road. Support structures, claddings, railings and handrails included bio-inspired design elements and bio-based materials, such as the Valsteeg viaduct cladding, which reportedly combines the striking visual aesthetic of weathered COR-TEN steel with the durability and weight reduction of a composite material.
Adequate water resources are creating new opportunities for composites. Composite materials play a role in seawater desalination as well as wastewater recycling and groundwater storage. Filament-wound fiberglass-reinforced plastic (FRP) pressure vessels hold the reverse osmosis (RO) membranes, which have proven an effective solution for producing clean water through municipal wastewater recycling and seawater reverse osmosis (SWRO) desalination. For example, the West Basin Municipal Water District in Carson, Calif., currently has a total of 1,238 fiberglass pressure vessels, nearly all rated at 450 psi, for RO processing at recycling facilities in El Segundo, Torrance and Carson. The recycled water is delivered to the Water Replenishment District, which manages and protects local groundwater for 4 million residents over a 420-square-mile region of southern Los Angeles County. The 43 cities in its service area use ~225 million gallons/day (~82 billion gallons/year), or about half of the region’s water supply.
Another example is Pure Water San Diego, a phased, multi-year wastewater treatment program that will provide one-third of San Diego’s water supply locally by 2035. A demonstration facility has produced 1 million gallons/day (mgd) of purified water since June 2011, using 37 RO fiberglass pressure vessels rated for 300 psi, made by Protec-Arisawa (Vista, Calif., U.S.). An additional 1,400 pressure vessels will be installed for Phase 1, which will produce 30 mgd. Phases 2 and 3, which will provide another 53 mgd by 2035, will also require pressure vessels. The ground water replenishment system at California’s Orange County Water District facility uses reverse osmosis via 3,150 fiberglass pressure vessels, 25 feet x 8 inches in diameter, manufactured by Protec-Arisawa. Each vessel is loaded with seven RO membrane elements.
According to an August 2020 release by Market Watch : “A growing and likely huge, sustainable market for pressure vessels is the growing construction of seawater reverse osmosis [SWRO] desalination plants. SWRO depends on membrane systems that serially cleanse water piped onshore from the ocean. These membranes must be encased in membrane housings. Filament-wound fiberglass pressure vessels are used almost exclusively for this purpose today, in quantities of as many as 6,000 per desalination plant.” The market is estimated to grow by 5.2% annually from 2021-2026.
Meanwhile, Orenco’s AdvanTex Treatment Systems have been providing reliable, energy-efficient wastewater treatment for more than 15 years. The AX-Max is pre-plumbed and easy to install. The entire system — including treatment, recirculation and discharge — is built inside an insulated glass fiber composite tank that ranges from 14-42 feet (4.3-12.8 meters) in length. Orenco Composites uses filament winding and two types of closed-molding processes — resin transfer molding (RTM) and vacuum infusion — to produce high-quality, single-piece infused FRP composite parts. The company has taken the fiberglass technology developed for wastewater markets and created high-quality buildings, basins, tanks and enclosures for a wide variety of markets.
Composites fabricator Soling (Estrella, Antioquia, Colombia) manufactured 840 composite covers using RTM to cover the Casablanca water storage tank in Bogotá, Colombia, which holds up to 38 million gallons of water and is the largest water storage system in the country. Each domed, rectangular composite cover measures 7.6 meters long and 2.4 meters wide (24.9 x 7.9 feet) and is made from glass fiber fabrics and polyester resin. The new covers offer a safer, lighter and more durable replacement for previous covers made from concrete and asbestos, which posed a significant threat to water quality and human health, were prone to failure and were expensive to maintain.
There is a sea change in the use of composites for infrastructure, says Gregg Blaszak, co-founder of Coastline Composites (Lancaster, Pa., U.S.), a consulting firm that works with FRP composite manufacturers. “We’ve started to see more engineers really take a hard look at these types of materials because they are, for the most part, maintenance free.” One example, he says, is the increasing number of projects specifying fiberglass rebar for reinforcing concrete structures as an alternative to traditional steel rebar.
“I expect to see the continued development of fiberglass rebar in structural applications and increasingly in flatwork applications,” says Christopher Skinner, vice president, strategic marketing, composites, for Owens Corning (Seward, Neb., U.S.). “Contractors are seeing increased strength and weight reduction versus steel which significantly increases productivity for their crews. I expect that the durability of composite materials will soon be factored into purchase decisions.”
Roughly 11,000 kilometers of GFRP rebar reinforce this concrete flood mitigation channel in Jizan, Saudi Arabia, and enable its 100-year service life. Photo Credit: Mateenbar
Mattenbar (Dubai, UAE and Concord, NC, U.S.), a supplier for the largest FRP rebar project in the world, the 23-kilometer-long Jizan Flood Channel in Saudi Arabia, agrees. The Jizan Tunnel project is seen as a significant turning point in the infrastructure sector. With a long and costly history of corrosion worldwide, steel is no longer viewed as a cost-effective option in aggressive environments. The ASTM standards and ACI codes were already in place, says Mateenbar CEO Nick Crofts. “Saudi Aramco simply mandated the use of FRP rebar and, notably, that did not increase the cost of the flood channel, which surprised a lot of people.” Crofts points out that the installation of FRP rebar for the Jizan Flood Channel was much faster than what contractors and project managers were accustomed to with steel rebar. He sees Jizan as a watershed moment in concrete reinforcement and the anticipated growth in such projects is already justifying multiple factories worldwide.
In June 2021, Saudi Aramco inaugurated the first GFRP rebar facility in Saudi Arabia. The IKK Mateenbar plant was established by Pultron Composites (Gisborne, New Zealand) in partnership with Isam Khairy Kabbani Group (IKK, Jeddah, Saudi Arabia) and Saudi Aramco (Dhahran, Saudi Arabia), and will manufacture and supply corrosion-free fiberglass rebar for infrastructure projects in Saudia Arabia, as well as the Middle East and North Africa regions.
Aramco has also partnered with the American Concrete Institute (ACI) to establish NEx: A Center of Excellence for Nonmetallic Building Materials to develop and promote the use of nonmetallic materials in the construction sector. Based at ACI World Headquarters in Farmington Hills, Mich., U.S., NEx will focus on accelerating the use of nonmetallic materials and products in construction and infrastructure. “Expanding incorporation of nonmetallic materials and products in the built environment will improve sustainability, contribute to a lower carbon footprint and enhance the durability and longevity of structures,” says ACI president Jeffrey W. Coleman.
CarbonCast technology saves weight and cost in precast concrete panels, thanks to carbon fiber reinforcement, which ties together concrete faceskins, placed in between EPS foam core. Photo Credit: Metromont
But glass fiber is not the only reinforcement that can significantly outperform steel in reinforcing concrete. Since 2004, Altus Group (Greenville, S.C., U.S.), an alliance of precast concrete manufacturers, has used CarbonCast high-performance insulated wall panels to enable construction that is lighter, thinner and stronger than most cast-in-place, solid precast and conventional steel-reinforced precast concrete wall systems. The panels comprise two concrete wythes (faceskins) separated by rigid foam insulation boards and connected by C-Grid (Chomarat North America, Williamston, S.C., U.S.) carbon fiber composite grid as shear trusses. Offering insulation values of R-37 or higher, CarbonCast panels can be manufactured from seven to 12 inches thick with widths up to 15 feet and heights of 50 feet or more. Because carbon fiber is much stronger than steel, panel size can be increased, meaning fewer pieces are produced and transported, so installation is faster and the overall carbon footprint during construction is smaller versus conventional precast systems. As of 2020, more than 1,500 CarbonCast projects had been completed, totaling 45 million square feet (4.2 million square meters).
Germany aims to take this technology even further, using CFRP grids to reinforce solid concrete construction of all kinds, dramatically reducing thickness, weight, installation and CO2 emissions. Established in 2006, the C³ - Carbon Concrete Composite project is the largest research project in the German construction industry, with more than 150 partners and 300 individual projects. Concrete is the world’s most widely used material after water, comprising cement, water and aggregate. The production of cement alone is responsible for 6.5% of total CO2 emissions, about three times that from global aviation. The German government announced in June 2020 that it will fund a new carbon fiber-reinforced concrete research center, aimed at increasing steel replacement and overcoming barriers to widespread adoption, including government-approved designs and standards. The German effort is led by long-time TU Dresden carbon fiber- and textile-reinforced concrete researcher, Dr. Manfred Curbach, who claims this technology can reduce concrete material use by 50% and CO2 emissions by up to 70%.
Kratos C-plate. Photo Credit: Kordsa
Other carbon fiber composites for infrastructure include the first such products in Turkey: Kordsa’s (Istanbul, Turkey) Kratos structural reinforcements which, to date, consists of Kratos C-fabric unidirectional (UD) carbon fiber fabric and Kratos C-plate pultruded carbon fiber strips. Designed to retrofit reinforced concrete structures, including in seismic retrofitting applications, these products are said to increase a structure’s load-bearing capacity and improve structural performance. For example, Kratos C-fabric with Kratos Prime resin is specifically used on reinforced concrete columns, shear wall and beam surfaces, with potential for use on concrete silos, bridges, viaducts and natural gas or oil pipelines. Kratos C-plates with Kratos adhesive is used specifically for reinforced concrete beams and slabs.
GFRP eliminates risk of corrosion and increases durability fourfold for reinforced concrete that meets future demands as traffic, urbanization and extreme weather increase.
The matrix binds the fiber reinforcement, gives the composite component its shape and determines its surface quality. A composite matrix may be a polymer, ceramic, metal or carbon. Here’s a guide to selection.
Tried-and-true legacy epoxies are a must for aerospace composites, but usage is increasing with improved forms.
© 2021 Gardner Business Media, Inc. Privacy Policy [Log On]