Question

An RC short column with 300 mm x 300 mm square cross-section is made of M-20 grade concrete and has 4 numbers, 20 mm diameter longitudinal bars of Fe-415 steel. It is under the action of concentric axial compressive load. Ignoring the reduction in the area of concrete due to steel bars, the ultimate axial load carrying capacity of the column is

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

Answer 1

The correct option is C 1198 kN

For short axially loaded column, Ultimate load carrying capacity,

$P_u=0.45f_{ck}.A_C+0.75f_y.A_{SC}$

Given,
$A_C=A_g$
So, $P_u=0.45\times 20\times 300\times 300+0.75\times 415\times 4\times \frac{\pi (20{)}^2}{4}$
= 1201 N
Nearest option is (c)