][ STEEL
STRUCTURES ][
][ STEEL
STRUCTURES ][
STEEL DECKS =========== Floor Decks: ========= 1. plywood 2. cast-in-place concrete light-weight concrete gypsum concrete 3. precast concrete 4. composition deck (concrete fill on formed sheet steel deck) Roof Decks: ========= 1. Formed sheet steel units with preformed rigid insulation 2. Formed sheet steel forming units with cast-in-place lightweight concrete 3. Gypsum concrete cast-in-place fill on combination form and ceiling finish units Steel Decks Manufacturer Specific - Proprietary Product: ========================================= 1. Type of Deck: ============ rip profile narrow rip -NR intermediate rip - IR wide rip deck - WR 2. Size of Deck: ============ specify: length width depth gage NR 22 = Narrow Rib 22 ga. NR 20 NR 18 IR 22 = Intermediate 22 ga IR 20 IR 18 WR 22 = Wide Rib 22 ga WR 20 WR 18 3. Deck Applications: ================ floor computer floor raised floor roof flat roof sloped roof 4. Load-Carrying Capacity: =================== Safe Load (Dead + Life) Table 9.4 P&A 301 40 psf 45 psf 69 psf 81 psf 145 psf 207 psf dead + live = number in parentheses ( ) assumes 10 psf dead load and l/240 max. live load deflection
5. Span Conditions: ============== simple span two bays three or more bays 6. Fire Rating: ========== concrete fill 7. Sound Transfer: ============== exposed suspended ceiling
Sample Problem-Simple Span Select the lightest steel deck for a simple span of 7 ft and a total load of 45 psf.
A. Given: ======= simple span 7 ft span 45 psf
B. Asked: ======= lightest deck
C. Graph: =======
D. Solution: ============ 1. Table 9.4 P&A 301 2. Simple span 3. 7 ft span column 4. look for 45 or next higher number 5. 46 = IR 18 = 2.7 psf = simple span (don't get confused with other columns for three and more spans) 6. (47) = WR 20 = 2.0 psf = simple span
E. Answer: ======== WR 20 2.0 psf simple span l/240 max. deflection
Select the lightest steel deck for a two-span condition and a span of 8.5 ft and a total load of 45 psf.
A. Given: ======= two-span 8.5 ft span 45 psf
B. Asked: ======= lightest deck
C. Graph: =======
D. Solution: ============ 1. Table 9.4 P&A 301 2. two span 3. 8.5 ft span - look in this column of the chart 4. look for 45 or next higher number 5. 57 = WR 18 = 2.7 psf = simple span (don't get confused with other columns for three and more spans)
E. Answer: ======== WR 18 2.7 psf two span l/240 max. deflection
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©Dr. Gruenwald 1996, 1997
