This document discusses concepts related to the density, specific gravity, and moisture absorption of aggregates used in construction. It defines density as the mass per unit volume of a material. Specific gravity is defined as the ratio of a material's density to the density of water. There are four moisture states for aggregates: oven dried, air dried, saturated surface dry (SSD), and soaked. The absorption capacity of an aggregate is its moisture content when in the SSD state. Several methods are described for determining the bulk specific gravity and absorption capacity of aggregates through experiments involving weighing samples both dry and saturated.