CE $221$ CONSTRUCTION MATERIALS

HOMEWORK $3$

DUE ON DECEMBER $10,2024$

latest at $5$:$00$ PM

Sieve analysis test results for two aggregates are given below. The aggregates will be mixed to have a fineness modulus of $3\mathrm{.}94.$ Portland cement $(d=3\mathrm{.}10k\frac{g}{d}{m}^3),$ water and the aggregate mixture will be used to produce concrete which will have plastic consistency and contain $2\%$ air content at fresh state.

Sand $,8,23,4560100100100,2\mathrm{.}60$

Gravel $1,3,7,12,20,55100,2\mathrm{.}65$

Preliminary design calculations showed that concrete will be produced using $750k\frac{g}{m^3}$ sand and $950k\frac{g}{m^3}$ gravel.

a$)$ Calculate the preliminary design value for the portland cement.

b$)$ Slump and density of the concrete produced in the laboratory were measured as $8$ cm and $2370k\frac{g}{m^3}.$ Calculate the actual weights of the materials used and the actual air content of the concrete.

Sieve analysis test results for two aggregates are given below.

Sand $,8,23,4560100100100,2\mathrm{.}60$

Gravel $,1,3,71220,55100,2\mathrm{.}65$

C$30$ concrete is produced using these aggregates and portland cement $(d=3\mathrm{.}15k\frac{g}{d}{m}^3,f_{cc}=42\mathrm{.}5$MPa $).$ Preliminary design showed that $190k\frac{g}{m^3}$ water is needed to achieve plastic consistency in fresh concrete containing $1\%$ entrapped air voids.

a$)$ Calculate the amount of portland cement, sand and gravel to be used for producing this concrete.

b$)$ Determine by explaining whether this concrete could be used for constructing a structure near to or on the cost.