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COST Input Form: Mixture Factors and Information

The first step in completing this form is to specify the number of factors (parameters) to be varied in the experiment.

COST requires that w/c (water-cement ratio by mass) or w/cm (water-cementitious materials ratio by mass) be one of the factors (this requirement incorporates two mixture components, water and cement, into one variable factor). Up to four additional factors may be varied (additional mixture components may be included as fixed factors), giving a maximum of five factors, or parameters, that can be varied. The number of trial batches (runs) required increases with the number of variable factors.

Number of parameters to vary:

The second step is to select w/c or w/cm as a variable factor and to provide cement information.

Select w/c or w/cm using the radio buttons (the depressed button corresponds to the activated selection) and enter min and max values for your selection, plus cement specific gravity and cost. (NOTE: The terms "min" and "max" refer to the low and high settings to be used in the experiment for a variable factor).

    min max cement specific gravity cement cost ($/kg)
    w/c w/cm

The third step is to select the other components to be included as factors (either variable or fixed), and to provide the required material information.

Mineral admixtures

    To include a mineral admixture as a variable factor, select "On" and enter the requested information (enter min and max values as percent cement mass replacement). To include a mineral admixture as a fixed factor, select "Off" and enter a non-zero fixed value as the "min" value. To exclude a mineral admixture, make sure "Off" is selected and the min value is zero (default). Please use underscores instead of spaces in mineral admixture type names.

    Type min max specific gravity cost($/kg)
    silica_fume
    fly_ash
    slag

Chemical admixtures

    To include a chemical admixture as a variable factor, select "On" and enter the requested information (enter min and max values as dosage in liters per kg of cement). To include a chemical admixture as a fixed factor, select "Off" and enter a non-zero fixed value as the "min" value. To exclude a chemical admixture, make sure "Off" is selected and the min value is zero (default). Please use underscores instead of spaces in the chemical admixture names.
    Type min max specific gravity % solids (by mass) cost ($/liter)

Aggregates (fibers): specified fraction

    To include an aggregate as a variable factor, select "On" and enter the requested information (enter min and max values as volume or mass fraction). To include an aggregate as a fixed factor, select "Off" and enter a non-zero fixed value as the "min" value. To exclude an aggregate, make sure "Off" is selected and the min value is zero (default). Please use underscores instead of spaces in aggregate type names.

    Type min max bulk specific gravity absorp. (%) moisture content (%) cost ($/kg)
    fine_agg
    coarse_agg

The fourth step is to provide additional information needed to generate the experimental plan.

Please select the number of center points to use in this study and enter a random number seed
(less than zero) to randomize the run order.

Select number of center points to run:
Random number seed less than zero:

The final step is to enter a filename (no extension) to store the mixture proportion information. This should be the same name that you used when specifying the response variables earlier.

    Filename (no extension, eight characters maximum):

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