ASTM C123

Lightweight Particles in Aggregate

Applicability: ASTM C123 determines the percentage of low-density materials (coal, lignite, chert, shale) in fine and coarse aggregates using sink-float separation in heavy liquid. It is primarily used to check compliance with ASTM C33 specifications for aggregate quality, ensuring harmful, soft, or porous particles are limited.

Purpose: ASTM C123 is a standard test method used to determine the percentage of lightweight particles (such as coal, lignite, chert, or shale) in fine and coarse aggregates via sink-float separation in a heavy liquid (typically 2.0 or 2.40 specific gravity). It measures the amount of lightweight materials in both fine and coarse aggregates that could affect concrete quality.