Fiber Reinforced Polymer Meets Modern Challenges
When Hurricane Sandy battered countries and states on the Atlantic in 2012, the United States was lucky to suffer no fatalities. Though no Americans died as a direct result of the storm, Sandy was the sixth-costliest hurricane in U.S. history and crippled many parts of the Atlantic coastline for weeks and sometimes months. Damage to transportation and infrastructure stalled the healing process for hard-hit places like New Jersey and New York. Take the New York subway system’s Canarsie Tunnel. Sandy flooded 3,445 feet of the 7,953-foot-long tunnel, damaging or ruining tracks, signals, switches, power, communication cables, lighting, cable ducts, and bench walls. The $477 million repair contract called for demolition and reconstruction of 60,000 linear feet of duct banks; 14,400 linear feet of track and track bed; 270,000 linear feet of cable ducts and repair of 7,000 feet of concrete lining and installation of tunnel lighting and fire systems. Worst of all: the repair contract estimated that MTA would have to suspend the L-train for 15 to 18 months while these repairs took place. New York couldn’t wait almost two years to recover from Hurricane Sandy. The city and the Metropolitan Transportation Authority (MTA) needed a solution that would repair the damage thoroughly, safely and much faster than 18 months. The best academic minds were consulted and recommended Fiber Reinforced Polymer (FRP) as the material of choice to speed up the process without sacrificing quality. The city then turned to Creative Composites Group (CCG) to source the needed solution: tunnel shrouds. Though they didn’t exist at the time, CCG worked with the New York City MTA and its engineering firm to de - liver a trailblazing solution. For rail platforms to utility poles to bulkheads and much more, FRP is the material of the moment, meeting the unprecedented challenges of the 2020s at the speed of business, even when that means inventing new uses for the material. Innovation And Design Flexibility Because FRP is a man-made material, it’s able to be changed and im - proved upon as new data and new demands arise. Creative Composites Group didn’t say, “FRP can’t do that” to the people of New York City. It was instead, “Let’s find a way.” FRP can meet an enormous variety of innovative needs due to its design flexibility. Take New York City’s first FiberSpan™ bridge deck for the West Thames Street pedestrian bridge. The prefabricated FRP decking traveled fully fabricated from Ohio to NYC in 2019. The 16-panel FRP deck features included curbs, access to utilities underneath and a long lasting, non-slip overlay of quartz aggregate polymer and is supported by a two-span steel lenticular truss bridge designed to meet perfor- mance requirements. These requirements included 90 PSF live load
and a deflection rating of L/360. The deck area totals 3,482 square feet, with individual deck panel dimensions of 12.9 feet by 12.9 feet, a deck depth of 4 inches and a deck weight of only 8.4 PSF. This innovative, flexibly designed structure was installed in just one night while Manhattan slept. FRP’s light weight means it can be in - stalled fast. Light And Fast, But Durable Comparing steel, concrete, wood, and FRP, a layperson might assume that the lightweight composite material couldn’t be as strong as the tra- ditional materials. But FRP is high-strength and moderately stiff with the design flexibility to optimize for the desired structural properties. The table below shows the strength-to-weight comparison of different construction materials; FRP’s low weight and high strength signifi - cantly reduces installation time and disruptions to transportation. The property combinations also give FRP a service life often much longer than traditional materials and consider utility poles. Designed to be
20
csengineermag.com
August 2022
Made with FlippingBook Annual report