Beams are horizontal components that support deck members like double tees, hollowcore and solid slabs and sometimes other beams. They usually are made in one of three key shapes: rectangular, inverted tee or L-shaped.
Beams can be reinforced with either prestressing strand or conventional reinforcing bars. The reinforcing will depend on the spans, loading conditions and the producer’s preferred production methods.
Prestressed beams are typically pretensioned and cast in a long-line set-up similar to what’s used for double tees. Beams that are reinforced with conventional rebar can be cast as individual components, in shorter forms made specifically for the size of the beam. They typically are cast in the same orientation as used in the final structure.
They can be cast in practically any size needed to satisfy structural requirements. Typical depths are 16 to 40 inches, while widths vary between 12 and 24 inches. The typical span-to-depth ratio ranges between 10 and 20.
Since beams are cast upright, the bottom, sides and ledges are cast against a form and will typically be provided with an “as cast” finish that results in a smooth, hard finish. The top is troweled by the finishing crew and can be smooth, roughened to simulate the finish of supported double tees (as in a parking structure) or intentionally roughened to create a bond with cast-in-place concrete poured on top of it.
For more information, contact a PCI Certified Manufacturer.