Problem $3\mathrm{.}1$

Given Information:

Coarse Aggregates

$$ Gravel with crushed particles

$$ NMAS $=$ in$.$

$$ Bulk oven$-$dry specific gravity $=2\mathrm{.}890$

$$ Oven$-$dry rodded density $=105$ pcf $(2835$ lb$/$yd$3)$

$$ Moisture content $=0\mathrm{.}4\%$

$$ Absorption $=4\mathrm{.}0\%$

Fine Aggregates

$$ Natural sand

$$ Bulk oven$-$dry specific gravity $=2\mathrm{.}598$

$$ Moisture content $=2\mathrm{.}0\%$

$$ Absorption $=1\mathrm{.}0\%$

$$ Fineness modulus $=2\mathrm{.}80$

Cement

$$ Specific gravity $=3\mathrm{.}15$

Strength Information

Specified strength of concrete $=4\mathrm{.}5$ ksi $($old data shows the standard deviation of the compressive strength is $300$ psi when more than $30$ samples are tested$).$

Project Environment

Concrete is to be used in an interior beam $($width of $12$ in$.)$ with both clear space between bars and clear cover of $3$ in$.$

Air Entrainer

None, as the concrete is not expected to be exposed to freeze$-$thaw conditions and deicing salts.

Design the concrete mix using the abbsolute volume method.