QUESTION $2$ : CONCRETE TECHNOLOGY

$[20$ MARKS$]$

$2\mathrm{.}1.$ You were task to perform quality check on the calculations done by the intern before approving the ordering of the materials required for concrete mix design of the $20m^3$ concrete using the specifications below.

Concrete mix with a compressive strength after $28$ days of $25$MPa. The cement that is going to be used is CEMI $32\mathrm{.}5$ with relative density of $3\mathrm{.}14.$ The stone that is available is a $19\mathrm{.}0mm$ stone with a dry compacted bulk density $($CBD$)$ of $1595k\frac{g}{m^3}$ and a relative density of $2\mathrm{.}72.$ A good, crusher sand with a fineness modulus of $2\mathrm{.}4$ and a relative density of $2\mathrm{.}7$ is going to be used for the mix. The slump on site is specified as $75mm.$ The concrete will be compacted at moderate vibration.

$2\mathrm{.}1\mathrm{.}1.$ Looking at the intern's calculations: Use the table below to perform your quality check. Appendix A for reference

$\backslash$table$[[,$Intern,Yourself,Justify your answer$],[$Water:cement ratio,$0\mathrm{.}53,(1),(1)$