[ G_sb(SSD) = \frac\textSSD mass\textSSD mass - (\textmass pycnometer + water to mark - mass pycnometer + SSD agg + water) ] Actually, simplified:
Bulk specific gravity is used in conjunction with the bulk unit weight (ASTM C29) to calculate the voids in the aggregate, which influences the workability and paste requirements of concrete.
Bulk Specific Gravity (Dry): Based on the oven-dry weight of the aggregate. [ G_sb(SSD) = \frac\textSSD mass\textSSD mass - (\textmass
Testing: The sample is placed in a pycnometer (flask) with water. The mass of the flask, sample, and water is recorded to calculate displacement. Equipment Required Balance: Accurate to 0.1g. Pycnometer: Usually a 500 mL volumetric flask. Mold and Tamper: Used specifically for the SSD Cone Test. Oven: Capable of maintaining 110 ± 5°C. Why Engineers Download the PDF
Fine aggregate’s specific gravity and absorption directly affect concrete mix design, workability, and strength. ASTM C128 provides a pycnometer method to measure: The mass of the flask, sample, and water
The objective is to find the precise moment the cone first collapses, indicating the threshold of the SSD state.
Specific gravity is used to convert aggregate weight to volume. For instance, if a mix design calls for a specific volume of sand, the specific gravity is required to calculate the required batch weight. An error in specific gravity will result in an incorrect yield or an imbalance in the cement-to-aggregate ratio. Mold and Tamper: Used specifically for the SSD Cone Test
Generally, aggregates with higher specific gravity are stronger and more durable. Step-by-Step Testing Procedure