Determine the amount of rebar needed for the CMU wall in Problem 13. In addition to the rebar shown in Figure 12.24, there is one #6 rebar located at either side of the overhead doors, which extend from the bottom of the door to 16 inches above the top of the door and two #4 rebar above the doors. Allow for two inches of cover on the vertical bars. Add 8 percent for lap and waste to the horizontal bars and 30 percent for lap and waste to the vertical bars.
What will be an ideal response?
The waste may seem high for the vertical bars. This is because they will be ordered in 5? to 5.5? lengths and lapped 1? to 1.5? to facilitate their installation. The vertical #5 bars are calculated as follows:
Number of spaces = 80? × 12 in per ft / 32? = 30 spaces
Add 1 to get the number of vertical bars – Use 31 bars. Half of these bars will be 17?2? (17?4? – 2?) and the other half will be 5?2? (17?4? – 12? – 2?) because they are above the overhead doors.
Total length of vertical bars (lf) = 16 bars × 17?2? per bar + 15 bars × 5?2? per bar = 352 lf
Total weight of vertical bars (pounds) = 352 lf × 1.043 pounds per lf = 367 pounds
Add for lap and waste.
Total weight of vertical bars (pounds) = 367 pounds × 1.30 = 477 pounds
There are eight vertical #6 bars 13?4? long (12? + 16?).
Total length of vertical bars (lf) = 8 bars × 13?4? per bar = 107 lf
Total weight of vertical bars (pounds) = 107 lf × 1.502 pounds per lf = 161 pounds
Add for lap and waste.
Total weight of vertical bars (pounds) = 161 pounds × 1.30 = 209 pounds
From Problem 13, there is 320? of lintel blocks with two #4 in them. This includes those above the doors. The length of the #4 rebar is 640? (2 × 320?).
Total weight of horizontal bars (pounds) = 640 lf × 0.668 pounds per lf = 428 pounds
Add for waste and lap.
Total weight of horizontal bars (pounds) = 428 pounds × 1.08 = 462 pounds
Total weight of rebar (pounds) = 477 pounds + 209 pounds + 462 pounds
Total weight of rebar (pounds) = 1,148 pounds
You might also like to view...
The by-pass valve on most passenger car oil filters will open when resistance to flow reaches about ____.
A. 8 psi B. 12 psi C. 14 psi D. 16 psi
Many prints specify sizes for fillets and rounds in a note, rather than dimensioning each one.
Answer the following statement true (T) or false (F)
Discuss how to safely use power tools
What will be an ideal response?
Where does the heat come from to evaporate water in a cooling tower?
What will be an ideal response?