$9.$ Using the tables from Chapter $9($which are attached to the exam$)$ and your knowledge of concrete admixtures $($both chemical and mineral$),$ design a concrete mixture proportion for a bridge deck. Your design should be in lb$/$yd$3.$ Also, prescribe a curing regimen for the concrete.

a$.$ Required compressive strength of $4000$ psi at $28$days

b$.$ Type I cement with a specific gravity of $3\mathrm{.}15$

c$.$ Coarse aggregate bulk density $($or dry rodded unit weight$)$ of $101$ lb$/$ft$3$ and a specific gravity of $2\mathrm{.}67.$ The nominal maximum aggregate size is $0\mathrm{.}75$ in$.$

d$.$ Fine aggregate with a fineness modulus of $3\mathrm{.}00$ and a specific gravity of $2\mathrm{.}65.$

a$.$ Required slump of $1$ to $4$ inches.

b$.$ Required total air content of $62\%.$