CompositesWorld
Issue link: https://cw.epubxp.com/i/517026
CompositesWorld.com 47 NEWS N E W S N S N E W S E N W S W High-Rise FRP for attachments, joints and installation. Kreysler's designers used AutoCAD (Autodesk Inc., San Rafael, CA, US) for construction documents, Rhino 3D (Robert McNeel & Associates, Seattle, WA, US) for 3D modeling (see Step 1, p. 46) and Revit (also by Autodesk) for building information modeling (BIM). Fabrication begins Under a design-assist agreement, a point is reached when the design is deemed ready to build, the project owner buys of on the fnal design with details, and the design-assist subcontractor is awarded the build contract — if it has maintained pricing and met all requirements. Kreysler explains, however, that when his company reached that point, "it was conditional upon our panels passing the NFPA 285 fre test. So that was the frst thing we did." He adds that it was not trivial to develop a composite system that would pass full-scale testing (at a cost of $100,000) with no guarantee on the outcome. Failure, however, would preclude the system's use above the expansion's fourth foor. "But in the end, we succeeded," says Kreysler (for that story, see "Learn More"). Finally, fabrication began. Because the façade would have a complex, nonrepeating and textured surface, tooling was a signifcant undertaking. More than 700 unique molds were CNC-machined from expanded polystyrene (EPS) foam (see Step 2). PowerMill software by Delcam (Birmingham, UK, now a subsidiary of Autodesk) translated CAD fles to CNC machine tool paths. After the foam was machined, it was covered in tin foil and waxed as a mold release surface. "We then attached fat aluminum sheets on the sides to make edges for each panel," says Kreysler. Tis turned the undulating foam into a rectan- gular box for easier handling. Because the face of each panel would be uniquely curved, but the backs of the panels would have to be fat in order to mate and attach properly to Enclos' fat unitized wall panels, he points out that the distance of the edge returns (i.e., from the curved front surface to the fat back surface) was not only diferent for each and every panel, but even for each panel's left and right edge (see bottom photo, p. 45). Gel coat was then sprayed onto each mold (see Step 3). Te gel coat is composed of a Polynt Composites (Carpentersville, IL, US) polyester resin base, with additives for fre- and UV-resistance. 5 Attachment plates for aluminum framing were then bonded to the FRP, enabling aluminum stifening ribs to be mechanically fastened down the length of each panel. 6 Sandblasting the gel coat to reveal the desired matte fnish was the fnal step before shipping the panels to Enclos. 7 At the Enclos facility, technicians assembled each unitized wall system panel for the SFMOMA expansion, and then attached the matching Kreysler FRP rain screen panel, like the one shown here as it is lowered onto an Enclos wall system panel. Source (Step 7) | Enclos Source (Steps 1-6) | Kreysler & Associates