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

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Design of Wood Members for Formwork 135
between a 3 × 4 S4S horizontal wood member and a 4 × 6 S4S shore is
assumed to be 2½ in. by 3½ in., or 8.75 sq in. For an allowable compression
stress perpendicular to grain of 565 lb per sq in., the allowable
load would be (8.75 sq in.)(565 lb per sq in.) = 4,943 lb.
Design of Forms for a Concrete Wall
The use of the equations and principles previously developed will be
illustrated by designing the forms for a concrete wall. The design will
include the sheathing, studs, wales, and form ties (refer to Figure 5-13).
In the design of wall forms, the thickness and grade of the plywood
are often selected based on the availability of materials. For this design
example, a ¾-in.-thick plywood from the Group I species with S-2
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stress rating has been selected. The lumber will be No. 2 grade S4S
Southern Pine with no splits. The following design criteria will apply:
1. Height of wall, 12 ft 0 in.
2. Rate of filling forms, 6 ft per hr
3. Temperature, 80°F
4. Concrete unit weight, 150 lb per cu ft
5. Type I cement will be used without retarders
FIGURE 5-13
Details of one side of wall form.
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