Test Summary: The sample of aggregate is sieved through a 4.75 mm sieve by dry sieving and washing to remove dust and other coatings from the surface. The material finer than 4.75 mm sieve is rejected (Specific Gravity test on material finer than 4.75 mm is conducted based on AASHTO T 84). The washed sample of aggregate is dried to constant mass at a temperature of 110 ± 5°C (230 ± 9°F). Once cooled, the sample is immersed in water to essentially fill the pores (by 15–19 h of soaking in water). It is then removed from the water, surface dried by a large absorbant cloth to reach Saturated Surface Dry (SSD) condition and weighed in air. Subsequently the sample is weighed while submerged in water maintained at a temperature of 23 ± 1.7°C (73.4 ± 9°F). The sample is dried again by oven drying and weighed. Using the formulas detailed below and using the mass and weight measurements made as described above, specific gravity and absorption calculations are made.
Bulk Specific Gravity, 23°C (73.4°F), is calculated based on the
Bulk Specific Gravity 23°C (73.4°F) in terms of saturated surface-dry (SSD)
condition is calculated based on the following formula.
Apparent Specific Gravity 23°C (73.4°F) is calculated based on the following
Percentage of Absorption is calculated based on the following
A = mass of oven-dry test sample in air, g;
B = mass of saturated surface-dry test sample in air, g;
C = mass of saturated test sample in water, g.