ASTM C638-20 PDF Download

ASTM C638-20 is a standard that provides a descriptive nomenclature for the constituents of aggregates used in radiation-shielding concrete. The purpose of this standard is to accurately describe the common or important naturally occurring and synthetic constituents of aggregates used specifically for radiation-shielding concrete. These constituents are not typically found in aggregates used for general concrete applications, as described in Descriptive Nomenclature C294. While some minerals and rocks discussed in this standard may be present in small quantities in general aggregates, they are not major constituents.

The standard includes descriptions of both naturally occurring and synthetic aggregates. The synthetic aggregates covered in this standard are ferrophosphorus and boron frit. However, it is important to note that the descriptions provided in the standard are not sufficient for the identification of materials. Accurate identification of natural and synthetic aggregate constituents requires the expertise of qualified professionals such as geologists, mineralogists, or petrographers, who utilize specific apparatus and procedures.

It is worth mentioning that the standard includes notes and footnotes that offer explanatory material. These notes and footnotes, excluding those in tables and figures, are not considered as requirements of the standard.