In a blended cement, the volume fractions of MA and cement are calculated on the basis of 100 g of binder, and the w/s ratio was used instead of the w/c ratio. Thus, the volume fractions of these two solid materials in the paste before hydration can be calculated as:
The degree of hydration of cement in the blended paste at time t, can then be calculated as:
The degree of reaction of the MA in the blended paste at time t, can be calculated as:
The standard deviation in the point counting is [14]:
where σp is the standard deviation in the point-counting measurement of P (%) for a given constituent, P is the phase percentage of the given constituent, and N is the total number of points counted. In the current study, N = 3000. This standard deviation in the phase volume fraction is then converted to the standard deviation in the degree of cement hydration:
where σα is the measured standard deviation for the degree of hydration as determined by point-counting. This is done similarly for the blended cements and standard deviation in the degree of reaction in the MA.