first and last studs must be placed at the ends of the form, even though the spacing between the last two studs may
be less than the maximum allowable spacing.
Step 16. Determine the number of wales for one side of a form by dividing the form height by the maximum wale
spacing, and round up to the next integer. Place the first wale one-half of the maximum space up from the bottom
and the remainder at the maximum wale spacing
Step 17. Determine the time required to place the concrete by dividing the height of the form by the rate of
placing.
Example Problem 1
Design the form for a concrete wall 40 inches long, 2 feet thick, and 10 feet high. An M919 concrete mobile
mixer is available, and the crew can produce and place a cubic yard of concrete every 10 minutes. The concrete
placing temperature is estimated at 70F. The form materials you have are 2-by 4-foot lumber, 1-inch board
sheathing, and No 9 steel wire.
Solution Steps:
Step 1. Materials available: studs, 2- by 4-foot (single); wales, 2- by 4-foot (doubled); sheathing, 1-inch board;
ties, No 9 wire.
Step 3. Plan area of form = 40 ft x 2 ft = 80 sf
Step 5. Concrete placing temperature = 70F
Step 6. Maximum concrete pressure (refer to Figure 3-3, page 3-5) = 400 lb/sf
Step 7. Maximum stud spacing (refer to Table 3-1, page 3-6) = 18 inches
Step 9. Maximum wale spacing (refer to Table 3-3, page 3-9) = 24 inches
Step 11. Tie wire spacing based on wale size (refer to Table 3-4, page 3-11) = 30 inches
3-13
EN5466
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