Question

A short RCC column is designed assuming maximum permissible axial compressive stresses in concrete and steel as:
1. 0.4 f_ck and 0.67 f_y respectively
2. 0.446 fck and 0.87 fy respectively
3. 0.67 fck and 0.67 fy respectively
4. 0.446 fck and 0.67 fy respectively

Answer 1

Correct Answer - Option 1 : 0.4 f_ck and 0.67 f_y respectively

The permissible design stresses for an RCC Column under different conditions are given below:

1. If minimum eccentricity is considered to be Zero i.e. e_min = 0

a. Permissible axial compressive stress in concrete = 0.45 f_ck

b. Permissible axial compressive stress in steel = 0.75 f_y­

2. If minimum eccentricity effect is considered: 

a. Permissible axial compressive stress in concrete = 0.4 f_ck

b. Permissible axial compressive stress in steel = 0.67 f_y­

Note:

In RCC beam subjected to bending, shear and torsion, the permissible values in steel and concrete are:

a. Design strength of concrete in flexure = 0.45 f_ck

b. Design strength of Steel in tension = 0.87f_y