Determine the 10mm vertical and horizontal reinforcement fr the CHB wall 4.0m length and 3.0m high. Reinforcement is spaced at 80cm on centers vertically and every three layers respectively.
a. Direct counting:
For horizontal reinforcement: Horizontal reinforcement is every three layers of CHB height as 0.20m, thus total height of each layer is 0.60m.
So, for horizontal reinforcement: 5 layers of 4.00m D10mm rebars.
For vertical reinforcement:
So, for vertical reinforcement: 5 layers of 3.00 D10 rebars.
To convert the needed steel bars in commercial sizes, the least wastage is by using 7.5m lengths cut into 4m and 3m (wastage: 0.50m each bar).
So, use: 5pcs D10mm x 7.50m RSB
b. Square Meter Method or Area Method:
For vertical reinforcement, using the table:
| SPACING | LENGTH OF BARS | LENGTH OF BARS |
|---|---|---|
PER BLOCK
|
PER SQ.M.
| |
cm.
|
m.
|
m.
|
40
|
0.235
|
2.930
|
60
|
0.171
|
2.130
|
80
|
0.128
|
1.600
|
Convert into commercial lengths: 4pcs D10mm x 5.00m
For horizontal reinforcement, using the table:
SPACING
|
LENGTH OF BARS
|
LENGTH OF BARS
|
|---|---|---|
LAYERS
|
PER BLOCK
|
PER SQ.M.
|
m.
|
m.
| |
2
|
0.264
|
3.30
|
3
|
0.172
|
2.15
|
4
|
0.138
|
1.72
|
This can be converted to: 4pcs D10mm x 5.00m
1pc D10mm x 6.00m
In summary, order: 8pcs D10mm x 5.00m RSB
1pc D10mm x 6.00m RSB
c. Unit Block Method. This method requires the number of CHB.
From the table above:
Vertical reinforcement:
Convert into commercial lengths: 4pcs D10mm x 5.00m
Horizontal reinforcement:
This can be converted to: 4pcs D10mm x 5.00m
1pc D10mm x 6.00m
In summary, order: 8pcs D10mm x 5.00m RSB
1pc D10mm x 6.00m RSB
Note: The results of the two last methods yield the total number of bars needed. The estimator would have no means of knowing the lengths of bars to be installed vertically and horizontally. Bar scheduling with these methods would be hard to identify.
Back to 7.0. Estimating Concrete Reinforcement
Easy way to compute👍
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