Civil Engineering Materials #$7\mathrm{.}6$

Using the following data for an unreinforced PCC Pavement slab:

Design strength $f^{\text{'}}c=4000$

Slab thickness $=12"$

Standard deviation of f$\text{'}$c obtained from $20$ samples$=200$psi

Ignore any exposure requirement.

Use air$-$entrained concrete.

Fineness modulus of fine aggregate $=2\mathrm{.}60$

Maximum aggregate size $=2"$ and nominal maximum aggregate size $=11/2"$

Bulk oven$-$dry specific gravity of coarse aggregate $=2\mathrm{.}6$

Oven$-$dry rodded density of coarse aggregate $=125$ pcf Find the following:

Required compressive strength.

w$/$c ratio

Coarse aggregate amount $(l\frac{b}{y}d{d}^3)$

If the $\frac{w}{c}$ ratio is $10\%$ reduced, will the quantity of coarse aggregate increase, decrease or remain the same? Explain your answer.