ASTM D7172-14 PDF Download

The ASTM D7172-14 standard is a method for determining the relative density (specific gravity) and absorption of fine aggregates using infrared technology. The purpose of this standard is to provide a standardized procedure for calculating the volume occupied by the aggregate in various mixtures, such as concrete and asphalt, by determining its bulk relative density. This value is important for accurately proportioning and analyzing mixtures on an absolute volume basis.

The standard also defines the concept of apparent relative density, which pertains to the relative density of the solid material making up the aggregate particles, excluding the pore space accessible to water. However, this value is not widely used in construction aggregate technology.

Water absorption values are another important parameter determined by this standard. These values are used to calculate the change in mass of the aggregate due to water absorbed in the pore spaces within the particles. The standard specifies that the absorption should be determined after submerging dry aggregate in water for approximately 24 hours. However, aggregates mined from below the water table may have higher absorption if not allowed to dry. Conversely, some aggregates may contain less absorbed moisture than the 24-hour soaked condition. In such cases, the percentage of free moisture can be determined by deducting the absorption from the total moisture content determined by drying.