Question

A certain R.C. short column with 300 mm square cross-section is made of M 20 grade concrete and has 4 numbers, 20 mm diameter, longitudinal bars of Fe415 grade steel. It is under the action of a concentric axial compressive load. Ignoring the reduction in the area of concrete due to the steel bars, the ultimate axial load carrying capacity of the column as by relevant code is

• A. 1069 kN
• B. 1198 kN
• C. 1548 kN
• D. 1659 kN

Answer 1

The correct option is B 1198 kN

$P_{uz}=0.45f_{ck}{A}_c+0.75f_y{A}_{sc}=[0.45\times 20\times (300\times 300)+0.75\times 415\times 4\times \frac{\pi }{4}(20{)}^2]\times \frac{1}{{10}^3}=120kN\simeq 1198kN$