ASTM C128 − 15 Standard Test Method for Relative Density Specific Gravity and Absorption of Fine Aggregate

Scope of ASTM C128 − 15 Standard Test Method for Relative Density Specific Gravity and Absorption of Fine Aggregate

1.1 This test method covers the determination of relative density (specific gravity) and the absorption of fine aggregates. The relative density (specific gravity), a dimensionless quality, is expressed as oven-dry (OD), saturated-surface-dry (SSD), or as apparent relative density (specific gravity).

The OD relative density is determined after drying the aggregate. The SSD relative density and absorption are determined after soaking the aggregate in water for a prescribed duration.

1.2 This test method is not intended to be used for lightweight aggregates that comply with Specification C332 Group I aggregates. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard

Significance and Use of ASTM C128 − 15 Standard Test Method for Relative Density Specific Gravity and Absorption of Fine Aggregate

5.1 Relative density (specific gravity) is the ratio of mass of an aggregate to the mass of a volume of water equal to the volume of the aggregate particles – also referred to as the absolute volume of the aggregate.

It is also expressed as the ratio of the density of the aggregate particles to the density of water. Distinction is made between the density of aggregate particles and the bulk density of aggregates as determined by Test Method C29/C29M, which includes the volume of voids between the particles of aggregates