Formwork for Concrete Structures by R.L.Peurifoy and G.D- By EasyEngineering.net

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Forms for Walls 219
Item
Plyform
Class I
Plyform
Class II
Structural I
Plyform
Bending stress, lb/in. 2 F b
1,930 1,330 1,930
Rolling shear stress, lb/in. 2 F s
72 72 102
Modulus of Elasticity—(psi,
adjusted, use for bending
deflection calculation)
Modulus of Elasticity—(lb/in. 2 ,
unadjusted, use for shear
deflection calculation)
E 1,650,000 1,430,000 1,650,000
E e
1,500,000 1,300,000 1,500,000
Note:
1. Courtesy, APA—The Engineered Wood Association.
TABLE 9-4 Allowable Stresses for Plyform, lb per sq in.
Equations for Calculating Allowable Span Lengths, in Inches, of Wood
Beams
Bending Deflection
Span
Condition
Bending l b
, in.
Shear l v
, in.
l D
, in. for
D = l/360
l D
, in. for
D = 1/16-in.
Single
spans
[96F b
S/w] 1/2
Eq. (5-30)
16F v
bd/w + 2d
Eq. (5-32)
ww.EasyEngineering.n
[4,608EI/1,800/w] 1/3
Eq. (5-33a)
[4,608EI/80w] 1/4
Eq. (5-33b)
Multiple
spans
[120F b
S/w] 1/2
Eq. (5-34)
192F v
bd/15w + 2d
Eq. (5-36)
[1,743EI/360w] 1/3
Eq. (5-37a)
[1,743EI/16w] 1/4
Eq. (5-37b)
Notes:
1. Physical properties of wood beams can be obtained from Table 9-1.
2. See Tables 4-2 and 4-3 for allowable stresses with adjustments from Tables 4-3a
through 4-8.
3. Units for stresses and physical properties are pounds and inches.
4. Units of w are lb per lineal foot along the entire length of beam.
TABLE 9-5 Equations for Calculating Allowable Span Lengths, in Inches, for
Wood Beams Based on Bending, Shear, and Deflection for Beams with Uniformly
Distributed Loads
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