Problem $2$

A $4\mathrm{.}8m$ tall $350mm350mm$ concrete column is reinforced with $8-20M$ rebar as shown in the

drawing below. This composite column supports a compressive force of $1250kN.$ Use $E_{\text{c}\text{o}\text{n}\text{c}\text{r}\text{e}\text{t}\text{e}}=$

$24{10}^3$MPa and $E_{\text{r}\text{e}\text{b}\text{a}\text{r}}=2{10}^5$MPa. The area of each $20M$ bar is $300m{m}^2.$

a$.$ Calculate the total axial force in all the rebar $($Hint: treat all the rebar as one total area of

rebar$).$ Report your answer in $kN.$

b$.$ Calculate the axial force in the concrete. Report your answer in $kN.$

c$.$ Calculate the displacement of the top of the column. Report your answer in mm$.$

d$.$ Calculate the stress in the rebar and the stress in the concrete.

e$.$ Explain why one material experiences more stress than the other material.