Question

The main reinforcement of a R.C. slab consists of 10 mm bars at 100 mm spacing, if it is desired to replace the 10 mm bars by 12 mm bars, then the spacing of 12 mm bars should be

• A. 120mm
• B. 140mm
• C. 144mm
• D. 160mm

Answer 1

The correct option is C 144mm

It spacing of 12 mm bars is S then

$\left(\frac{1000}{100}\right)\times \frac{\pi \times {10}^2}{4}=\left(\frac{1000}{S}\right)\times \frac{\pi \times {12}^2}{4}$

$\Rightarrow S=144mm$