offloaded and moved the sections to a staging area where workers installed the hardware before hoisting them to the bridge deck one by one with a small crane. “They had to have all the hardware on before they flew the panels up,” says Dinmore. “That was the only way to achieve the production rate of one minute per linear foot.” The hardware on each panel includes swivel hoist rings (aka swivel lifts), and two eye bolts, primary ties, and secondary ties. Skanska- Walsh workers waited on the bridge deck as sections were floated into place like puzzle pieces. The panels featured a notch slightly greater than 90-degrees along the bottom longitudinal edge that rested directly upon the top outboard flange of the fascia beam. Once the connection was engaged, a worker bolted the ties onto a threaded stud shot on the beam and tightened it. The swivel lifts were disconnected from the panel and flown back down with the rigging on the crane hook and the process was repeated on the next section. Another set of swivel lifts were used on the next section to save time. The plus 90-degree angle of the notch, better known as the bird’s beak, allows a panel to be set at almost any angle without any chipping or breakage. And it fits nearly any member that might be used for a bridge fascia beam. The only requirement is a 90-degree edge along the beam, whether curved, straight, concrete, or steel. No positive connection is made between the notch and the beam’s flange. “The notch is the secret sauce,” says Dinmore. “It’s what makes Precasteel work.” Safer than the Conventional Method Precasteel was initially designed to improve productivity, but it turned out that the conventional method of installing parapets was causing safety headaches. Dinmore was approached by several insurance agents at the 2018 Util - ity & Transportation Contractors Convention of New Jersey (UTCA NJ) in Atlantic City. All were seeing frequent safety claims associated with the improper installation of bridge brackets or the vulnerability to wind uplift causing damage prior to concrete placement. The bracket and plywood are often unsecured before concrete is poured, acting like a kite that can get blown upward by moderate to heavy winds. “This is a typical scenario for a lot of contractors,” Dinmore says. “It has probably happened to most of them at least once.” Many owners now specify that a cable needs to be threaded through the brackets to prevent the brackets from falling into the roadway below after uplift- ing winds rip the entire forming system off the bridge. Skanska-Walsh crews were able to work safely from the bridge deck at LaGuardia, focusing on connecting the hardware properly. Each Pre - casteel section is equipped with two ties, one of which is redundant. Even in a worst-case scenario where a heavy load bangs into a panel, it would break rather than fall. This was proven on the last barrier pour on a section installed more than 6 months before barrier concrete placement. Precasteel panels at LaGuardia were designed to withstand all anticipated construction and OSHA loads with up to six times the factor of safety on deck pours and two times on barrier pours; the cur -
rent standards have increased safety factors even more to facilitate the usage of pick brackets attached to the panels on the inside to allow workers to move freely up and down the line of panels and to account for reverse stresses that could be implied on the panels during slip forming operations. At 42 inches tall from the soffit top, the installed Precasteel panels eliminated the need for fall protection, which is required when using bridge brackets. This not only prevented tripping and other nuisances that arise when connecting self-retracting lifelines, but also improved productivity for the trades waiting behind Skanska-Walsh’s panel in - stallation crew. The time savings gained by not having to tie off were incremental at the end of the project but the real schedule booster was not having to come back after the panels were installed; hence the Precasteel motto, “Set ‘em & Forget ‘em!.” Skanska-Walsh finished successfully installing all Precasteel panels on the Central Terminal project in September 2019, and Delta Airlines had designed approximately 1,700 linear feet of Precasteel panels into the project at its neighboring terminal. DeFoe Construction Inc. had been slated to perform the work in early 2020; however, the pandemic caused precast plant closures that resulted in the need for conventional construction. The fact that Delta Airlines incorporated the panels into their design after witnessing the ease of construction and aesthetically pleasing finish is a testament to Precasteel. Dinmore was proud to see Precasteel reaching the tipping point after more than 20 years of seeking a solution and six years researching and developing the concept. “My goal is to see Precasteel on bridges in every state across this great nation and eventually the world,” he says. “I’m thankful to Skanska-Walsh for recognizing the simplicity and potential of my idea and putting it to the ultimate test at LaGuardia.” But Dinmore does not consider himself a salesperson or a politician, nor does he have the distribution or manufacturing facilities in place that are needed to launch his product on the grand scale it deserves. Now that proof of concept is behind him and the Infrastructure Bill is imminent, he’s looking for a helping hand to reach his goal of getting SIPFF’s on bridges across the U.S. Go to www.precasteel.com if you want to lend a hand.
BRIAN M. FRALEY , Fraley Construction Marketing
January 2023 csengineermag.com
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