8.3 Design Limits
(a) Slabs without drop panels as given in 8.2.4... 5 in.
(b) Slabs with drop panels as given in 8.2.4........ 4 in.
Table 8.3.1.1—Minimum thickness of nonprestressed two-way slabs without interior beams (in.)^{[1]}
f_{y}, psi^{[2]} | Without drop panels^{[3]} | With drop panels^{[3]} | ||||
---|---|---|---|---|---|---|
Exterior panels | Interior panels | Exterior panels | Interior panels | |||
Without edge beams | With edge beams^{[4]} | Without edge beams | With edge beams^{[4]} | |||
40,000 | ℓ_{n}/33 | ℓ_{n}/36 | ℓ_{n}/36 | ℓ_{n}/36 | ℓ_{n}/40 | ℓ_{n}/40 |
60,000 | ℓ_{n}/30 | ℓ_{n}/33 | ℓ_{n}/33 | ℓ_{n}/33 | ℓ_{n}/36 | ℓ_{n}/36 |
75,000 | ℓ_{n}/28 | ℓ_{n}/31 | ℓ_{n}/31 | ℓ_{n}/31 | ℓ_{n}/34 | ℓ_{n}/34 |
^{[1]}ℓ_{n} is the clear span in the long direction, measured face-to-face of supports (in.).
^{[2]}For f_{y} between the values given in the table, minimum thickness shall be calculated by linear interpolation.
^{[3]}Drop panels as given in 8.2.4.
^{[4]}Slabs with beams between columns along exterior edges. Exterior panels shall be considered to be without edge beams if α_{f} is less than 0.8. The value of α_{f} for the edge beam shall be calculated in accordance with 8.10.2.7.
Table 8.3.1.2—Minimum thickness of nonprestressed two-way slabs with beams spanning between supports on all sides
α_{fm}^{[1]} | Minimum h, in. | ||
---|---|---|---|
α_{fm} ≤ 0.2 |
8.3.1.1 applies |
(a) | |
0.2 < α_{fm} ≤ 2.0 | Greater of: | (b)^{[2],[3]} | |
5.0 | (c) | ||
α_{fm} > 2.0 | Greater of: | (d)^{[2],[3]} | |
3.5 | (e) |
^{[1]}α_{fm} is the average value of α_{f} for all beams on edges of a panel and α_{f} shall be calculated in accordance with 8.10.2.7.
^{[2]}ℓ_{n} is the clear span in the long direction, measured face-to-face of beams (in.).
^{[3]}β is the ratio of clear spans in long to short directions of slab.
(a) Nonprestressed slabs not satisfying 8.3.1
(b) Nonprestressed slabs without interior beams spanning between the supports on all sides and having a ratio of long-to-short span exceeding 2.0
(c) Prestressed slabs