Concrete Products

SEP 2015

Concrete Products covers the issues that attract producers of ready mixed and manufactured concrete focusing on equipment and material technology, market development and management topics.

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Page 42 of 59 September 2015 • 41 FEATURE FINFROCK A NEW BUILDING METHOD It was a 10-year process for the DualDeck to become a reality. Finfrock estimates that the company went through 50 different variations, and continues to find tradeoffs to limit site work. For instance, layout of stud walls using a 3D laser didn't come about until pour 6 or 7 for the Hyatt House project after an employee's suggestion. One person is now able to mark the form for the studs in less than 15 minutes uti- lizing the laser. This saves a lot of time in the field and provides better accuracy compared to using a measuring tape. The DualDeck is comprised of two flat slabs joined by steel tension and compression members, resulting in a composite truss that when placed in a multistory building, such as the Hyatt House Naples, becomes the finished ceiling of one level and the floor of the level above. Because panels are poured upside down and flipped over, both sides of the product are perfectly flat. There is almost no camber in the product. "A double tee can camber 1–2 inches; this product may have a ½ inch of camber if that," says Dan Finfrock. The interstitial space between the two con- crete surfaces provides an area for the mechan- ical, electric, plumbing, and fire protection subsystems. These are placed during DualDeck fabrication. Finfrock utilizes StructureWorks' technology (see sidebar on page 42) for the 3D modeling and laser projection for placement of the utilities. Subcontractors for the plumbing and electrical components also utilize the 3D laser, which is calibrated every two hours and has an accuracy of ½ mm, to set the height and position. Putting the mechanical, electric, plumbing, and fire protection components inside the DualDeck in a controlled, CAD/ CAM environment is a huge benefit because it speeds up construction, guarantees accuracy, and minimizes building obsolescence. For the Hyatt project, DualDeck spans are typically 40–65 ft. long and 12 ft. wide, with a 16–24 in. depth. Narrower and longer panels can be poured. The company typically pours 400 linear feet, 12 ft. wide every other day for the hotel project. The top prestressed concrete panel is cast first and after curing for 12 hours is inverted and mated with the highly pre- stressed bottom member. A self-consolidating mix is used on both the top and bottom panels, the latter using Fibermesh-dosed mixes. The truss consists of vertical angles spaced approx- imately 2 to 3 feet on center in each direction, and sloping D-20 deformed wires connecting the top of one angle to the bottom of an adja- cent angle. A span can have up to 11 rows of trusses; all are gang pressed to set. No welding is done until the end assembly for the entry tunnel to the interstitial space. POSITIVE FEEDBACK Finfock Industries has already received posi- tive feedback from potential owners that see DualDeck as minimizing their chance of having building obsolescence. With cast-in- place concrete there is only so many places one can core drill but with the DualDeck, the interstitial space allows someone to crawl inside. Typically, if a building is going to be completely renovated, an x-ray machine will need to be brought in to find the location of the utilities. However, with the use of Struc- tureWorks technology, Finfrock can pull up files illustrating the precise location of these components. Furthermore, the prod- uct's long-span capabilities make interior layout and future renovations much more flexible since there are fewer load-bearing walls as there are with tunnel forms. Another benefit is that there is a lot of overlap. Individual drawings are being pro- duced while pieces are being erected, reduc- ing a lot of trades and onsite disruption. Fewer onsite workers are needed, which is great for small, tight sites. Since the entire building as well as the DualDeck is mod- eled using StructureWorks software prior to manufacturing, Finfrock can see if there will be any clashes, eliminating field fixes. Initial cost of the DualDeck itself is equal to or slightly above a double tee but, the pro- ducer notes, all the tradeoffs make it worth it. Laser deployment on wall production in some cases has saved 50 percent on labor. Finfrock is still waiting to see what it will be for the DualDeck but estimates a 40-50 percent savings. Continued on page 42 The top panel of a DualDeck is lifted from numerous points (up to 22 on certain spans) and is moved over to a fipper located in the center of the production area. Once lowered onto the fipper, suction plates will adhere to the panel before it is inverted.

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