Assignment Instructions:

$1.$ Objective:

$$ Design a concrete mix meeting the specified conditions and specifications.

$$ Consider the given materials and their properties for the mix.

$2.$ Requirements:

$$ Compressive Strength $($f$$cr$)$: $35$ MPa at $28$ days.

$$ Air Entrainment: Required.

$$ Slump: Between $25$ mm and $75$ mm$.$

$$ Nominal Maximum Size Aggregate: $25$ mm$.$

No statistical data on previous mixtures are available.

$3.$ Materials Available:

$$ Cement: Type GU $($ASTM C$1157),$ relative density of $3\mathrm{.}0.$

$$ Coarse Aggregate: Well$-$graded, $25$ mm nominal maximum$-$size rounded gravel

$($ASTM C$33),$ with various properties. Standard Specifications for Concrete

Aggregates $($AASHTO M$80)$ with an oven dry relative density of $2\mathrm{.}68,$ absorption of

$0\mathrm{.}5\%($SSD$),$ and oven dry rodded bulk density $($unit weight$)$ of $1600$ kg$/$m$3$

$.$ The

laboratory sample for trial batching has a moisture content of $2\%.$

$$ Fine Aggregate: Natural sand $($ASTM C$33[$AASHTO M $6])$ with an oven dry relative

density of $2\mathrm{.}64$ and absorption of $0\mathrm{.}7\%.$ The laboratory sample moisture content is

$6\%.$ The fineness modulus is $2\mathrm{.}80.$

$$ Air$-$Entraining Admixture: Wood$-$resin type $($ASTM C$260).$

$$ Water Reducer: ASTM C$494,$ known to reduce water demand by $10\%$ at a dosage rate

of $3$ g$/$kg of cement.

$4.$ Additional Information:

$$ Assume the density of chemical admixtures is similar to water $(1$ Ml $=1$ g$).$

$$ Laboratory samples for trial batching have specified moisture content.

$5.$ Procedure:

$$ Use the Absolute Volume Method $($Metric$)$ to proportion the mix.

$$ Calculate the absolute volumes of each material.

$$ Adjust the water content considering the water reducer admixture