Question $2$:

The column shown below is subjected to a compressive axial force of $900kN$ and is reinforced with four pieces of rebar.

Assume:

$0\mathrm{.}3$ of the force is carried by the steel and $0\mathrm{.}7$ by the concrete,

$E_{\text{S}\text{T}\text{E}\text{E}\text{L}}=200000$MPa,$E_{\text{C}\text{o}\text{N}\text{C}}=25000$MPa

Compute the following :

Diameter of each rebar

Change in length of the column

Stress in concrete

Stress in Steel