Civil Engineering Materials #$7\mathrm{.}9$

Design the concrete mix according to the following conditions:

Design Environment

Pavement slab, Bozeman, Montana $($cold climate$)$

Required design strength $=3000$

Slab thickness $=12in.$

Statistical data indicate a standard deviation of compressive strength of $250$ psi is expected $($more than $30$ samples$).$

Only air entrainer is allowed.

Available Materials

Air entrainer: Manufacture specification is $0\mathrm{.}15$flo$\frac{z}{1}\%$ air$/100$ lb cement.

Coarse aggregate: $2$ in$.$ nominal maximum size, crushed stone

Bulk oven$-$dry specific gravity $=2\mathrm{.}573,$ absorption $=2\mathrm{.}8\%$

Oven$-$dry rodded density $=120pcf$

Moisture content $=1\%$

Fine aggregate: Natural sand

Bulk oven$-$dry specific gravity $=2\mathrm{.}540,$ absorption $=3\mathrm{.}4\%$

Moisture content $=4\mathrm{.}5\%$

Fineness modulus $=2\mathrm{.}68$