Which factor is NOT considered when determining the moisture content of aggregates?

When determining the moisture content of aggregates, it is essential to consider various factors that can impact the accuracy of the measurement. Temperature of drying is important because it affects evaporation rates; using too high a temperature could lead to inconsistencies. The size of the aggregate also plays a role, as different particle sizes can retain moisture differently and affect the overall moisture content readings. Duration of drying is another critical factor, ensuring that the aggregates are dried sufficiently for accurate moisture content determination—if not dried long enough, retained moisture could skew the results.

The amount of dust on aggregates, while it can affect the final product in terms of workability and bonding in concrete, does not directly influence the measurement of moisture content. Dust might retain some moisture, but it is not a primary factor affecting the calculation of the moisture content in the context of aggregate testing. Thus, this choice stands apart from the others, as it does not have a direct impact on the moisture content calculations required for proper aggregate assessment.