A Simplified Design Approach - Simplified Design of Reinforced Concrete Buildings - page 8

1.7.1 Building No. 1—3-Story Pan Joist Construction

(1) Floor system: one-way joist slab

Alternate (1)—standard pan joists
Alternate (2)—wide-module joists

(2) Lateral-force resisting system: beam and column framing

(3) Load data: roof LL = 12 psf

DL = 105 psf (assume 95 psf joists and beams + 10 psf roofing and misc.)

floors LL = 60 psf

DL = 130 psf (assume 100 psf joists and beams + 20 psf partitions +
10 psf ceiling and misc.)

(4) Preliminary sizing:

Columns interior = 18 18 in.

exterior = 16 16 in.

Width of spandrel beams = 20 in.
Width of interior beams = 36 in.

(5) Fire resistance requirements:

floors: Alternate (1)—1 hour

Alternate (2)—2 hours*

roof: 1 hour

columns: 1 hour**

Figure 1-3 shows the plan and elevation of Building #1.

* In some cases, floors may be serving as an “occupancy separation” and may require a higher rating based on building type of
construction. For example, there may be a mercantile or parking garage on the lowest floor.
** Columns and walls supporting two hour rated floor, as in Alternate (2), are required to have a two hour rating.