CompositesWorld
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CompositesWorld.com 71 NEWS N E W S N S N E W S E N W S W HOW TO KEEP THE AERODYNAMIC SHAPE EVEN UNDER EXTREME LOADS? THE ANSWER >> LOCTITE EPOXY FILM ADHESIVES ALL BENEFITS ON BOARD WITH LOCTITE EA 7000 AERO >> For wing to skin bonding and other aircraft structures, this epoxy flm adhesive ofers you: Henkel is engineering the future of composites. www.henkel-adhesives.com/wings > Environmental resistance to hydraulic fuids, fuel, and solvents > Excellent service temperature > Compatibility with prepregs > Dual temperature cure capabilities 250°F/121°C or 350°F/177°C > Global availability When the concrete was fully cured, the wooden strip was removed, which provided space to pull out the PVC pipe. Te frst units weighed 163-181 kg and measured 0.91m long, with an outside diameter of 46 cm, an inside diameter of 34 cm and 5.1 to 6.4-cm-thick walls. Lutey reports they achieved an extremely robust cure. "You could hit the FHSUs with a hammer and the concrete wouldn't break," he recalls. Te frst 50 units were trucked to prese- lected sites, lifted by boom onto a barge, and set onto the river bottom by a team from Friends and IDNR just before the river froze. By that time, Friends and IDNR had already released 55,000 channel catfsh fry into the river. Lighter Generation 2 deployed Tis May, IDNR and Friends surveyed the pilot site via underwater camera and found that the FHSUs hadn't moved or sunk into the riverbed, so the team moved forward with plans to make another 350 units this spring and summer. Since then, 100 units have been produced and installed, but with design changes to improve handling and stability. Te geotextile kelp was eliminated and the concrete foot was replaced by wooden risers. To reduce weight so FHSUs were easier to transport, the concrete was modifed with a lighter aggregate, reducing unit mass to about 100 kg. Tis time, FHSUs were lashed, several feet apart, to wooden pallets in pairs before they were placed into the river. Te thinking was this would keep the fsh houses from sinking into the silt should the riverbed erode. (Te pallet wasn't expected to rot very quickly since the water is fairly anaerobic.) However, this design also proved challenging because the pallets tended to fip over in the water, and banding that held the FHSUs to pallets could loosen. "Tis is an evolving project," concedes Lutey. "Te design is still changing." Friends and IDNR have since released the remaining 45,000 catfsh fry plus an additional 100,000 to help build a strong population. Frisbie notes that the IDNR does fsh surveys across the state on a rotating basis and will check progress in areas where FHSUs have been placed in about three years. "It'll be a little while before we fnd out how the catfsh are doing, but hopefully, the FHSUs turn out to play a strong role in their return." Read this article online: short.compositesworld.com/Catfish Contributing writer Peggy Malnati covers the automotive and infrastructure beats for CW and provides communica- tions services for plastics- and composites-industry clients. peggy@compositesworld.com Basalt-reinforced Rebar for FHSUs