The floor is leveled while diaphragm connections are welded. Where different-sized web membersconnect, a full-depth vertical weld is used, preventing the connection from acting as a hinge. The weld patterns are twice as long as design requirements, Ambrose explains. The last steps are to weld the joist shoes to the embeds and grout the slab's joints.
Construction speed is a key attraction to the system. The producer emphasizes the benefits of using precast concrete—minimal material handling, durability, no scaffolding, and offering a recyclable product. Supranos' engineers supply a layout and engineering plan. “We try to create the most economical design layout and adjust details to ensure everything works smoothly,” Ghazal says. “We like to show clients alternatives to make the process efficient. Materials are expensive so any changes can be worthwhile.”
By serving as the single-source provider for the materials, there is no onsite responsibility for accepting delivery and unloading joists and forming systems.
The producer's erection team can set 10,000 square feet in a day with no topping needed for leveling to save more time. The company prefers to be onsite before installation to review tie beams and embeds.
Often the producer is asked to supply the structural steel on the project. This provides another timesaving element to their service. Ghazal says wide disparities exist in the quality of shell with which they work. By being involved early in the design function, corrections can be easily made. “There is a fix for everything, but some projects require more fixes,” he says. “When we can control those details, we can ensure greater on-site coordination.”
The timesaving element continues once the producer leaves the jobsite. It begins with the masonry wall contractor who is installing the infill and exterior walls. Masons need only light-wheeled scaffolds to build the walls from the inside. “All we ask is that masons build walls to the correct line and level and that the corners are square,” Ambrose says.
The open-web design provides an additional construction benefit: Mechanical and plumbing lines fit neatly into the system's support. This open web design can provide the contractor more flexibility than precast concrete double-tees or hollowcore planks while retaining the benefits offered by other precast concrete elements.
The system has been installed in many types of residential and light commercial structures the past 12 years, accounting for more than 10 million installed square feet. Low-rise projects are most suitable, as the system's 17-inch depth can add significant height to a tall building. “Typically, our projects have been lower than six stories, but that's fine, because there are a lot of potential projects in that market,” Ambrose says. These opportunities include tract and custom homes, townhomes and apartments, institutional projects, schools, commercial properties, and industrial buildings.
In January, the producer was casting floor elements for a four-story custom home on Hutchinson Island designed by Kelly & Kelly Architects in Stuart, Fla. The triangular residence, situated on a small angular lot, required a 200 mph wind design. “Our system complies with hurricane wind level resistant building requirements found in South Florida, and it's hard to imagine anyone has a more restrictive code than that,” says Ambrose.
The first floor consists of 8-inch masonry walls and tie beams, while upper levels feature 6-inch-thick pre-insulated, precast concrete walls. The Supranos floors will serve as diaphragms, taking the vertical design loads and lateral wind loads into the walls and the foundations.
Extending the Reach
The drop-off in construction has led Supranos to examine licensing their system to other producers. This will extend the producer's delivery range. Currently, the company transports flooring within about a 300-mile radius of the South Florida plant.
We see possibilities for expanding to other areas, says Ambrose. With the number of repeat customers the producer has among architects and engineers, the management team thinks there's great potential.
The product would work well for precast concrete plants looking to expand their repertoire. The system can be produced anywhere in the country. “We've always had enough work to keep busy, but now it would make sense to expand to other plants by transferring our means and methods of creating the system,” says Ambrose.
To lean more about Supranos Systems visit www.supranosusa.com.
Craig Shutt is a contributing editor with James O. Ahtes Inc., with more than 30 years experience writing about construction. To contact him, you can firstname.lastname@example.org.