What is the formula to calculate Bulk Specific Gravity (BSG)?

The correct method for calculating Bulk Specific Gravity (BSG) involves using the dry weight of the material and the SSD (Saturated Surface Dry) weight. Specifically, BSG is calculated as the dry weight of the aggregate divided by the SSD weight.

The rationale behind this formula is that specific gravity is a measure of density relative to the density of water. When determining BSG, the SSD condition provides a consistent state for comparing the aggregate's mass to the equivalent volume of water it would displace. This condition helps eliminate the effects of surface moisture on the sample, providing a more accurate representation of the aggregate's density.

Using the formula correctly allows for the assessment of material properties essential for engineering applications, such as estimating voids in the aggregate and understanding how the material will behave when mixed with asphalt. Understanding how BSG plays into volume and density is fundamental in paving applications and quality control in asphalt mixtures.

The other options do not apply to the standard calculation of Bulk Specific Gravity, as they either misrepresent the relationship between weight measures or do not utilize the correct principles associated with specific gravity.