The Staybox system is prebent rebar and a formed metal box that creates a single “pull out” bar assembly. The assembly is used as a keyway and lap splice between concrete construction joints, including slab, deck, wall, beam and column intersections.
The metal box is formed in two pieces that slide together. The box is typically 1-1/2” deep; 2-1/2”, 3-1/2”, 6” or 8” wide; and 48” long. While those are standard sizes, the metal box can be fabricated to match other specifications or conditions.
The rebar is typically #3, #4 or #5 A706, with optional epoxy coating. The exposed rebar will be a straight, hook or stirrup type, depending on the application. The unseen portion of the rebar is prebent to fit inside the formed metal box.
The two-piece metal box is designed so the back plate remains in the concrete, while the front plate can be removed for access to the prebent rebar inside. The box itself and both ends are sealed to prevent concrete from seeping into the assembly.
The exposed Staybox rebar is tied to the main reinforcement and the metal box is fastened to the form face material. After concrete placement, the cover plate is removed and the prebent bars are straightened to provide a lap splice for subsequent pours.
The Staybox system provides a cost- and labor-saving solution for most concrete construction joints. There is no need to drill or alter the form face during installation. The prepositioned rebar provides alignment and load transfer between placements.