ASTM C331/C331M-17 PDF Download

The ASTM C331/C331M-17 standard is titled "Standard Specification for Lightweight Aggregates for Concrete Masonry Units." This specification provides guidelines for lightweight aggregates to be used in concrete masonry units with the main objective of reducing the density of the units.

The standard covers three general types of lightweight aggregates: those produced by expanding, palletizing, or sintering products such as blast-furnace slag, clay, diatomite, fly ash, shale, or slate; aggregates prepared from natural materials like pumice, scoria, or tuff; and aggregates consisting of end products of coal or coke combustion. The aggregates must predominantly consist of lightweight-cellular and granular inorganic material.

The standard sets requirements for the aggregates to ensure they do not contain excessive amounts of deleterious substances, as determined by organic impurities, staining, and loss on ignition tests. The aggregates should also meet specifications regarding clay lumps and friable particles, grading uniformity, loose bulk density, uniformity of loose bulk density, resistance to freezing and thawing, popouts, and drying shrinkage.

It's important to note that the specification includes explanatory notes and footnotes, which provide additional information but should not be considered as requirements of the standard.