ASTM C90-21 PDF Download

The ASTM C90-21 standard provides guidelines for the manufacture and use of concrete masonry units (CMUs) made from hydraulic cement, water, and mineral aggregates. These CMUs can be hollow or solid and are classified into three categories: normal weight, medium weight, and lightweight. The standard covers both loadbearing and nonloadbearing applications of these units.

The specification states that the CMUs can be made from lightweight aggregates, normal weight aggregates, or a combination of both. It clarifies that the requirements outlined in the standard have been established and researched for over a century to define the physical properties and attributes of CMUs. However, it also notes that while the standard covers many performance attributes, it may not address all pertinent physical properties necessary for real-world applications or for products manufactured using alternative materials, manufacturing methods, or curing processes.

The specification includes explanatory notes and footnotes, but these should not be considered as requirements of the standard, except for those in tables and figures. It also advises that if specific features such as surface textures, finish, color, or certain properties like density classification, compressive strength, fire resistance, thermal performance, or acoustical performance are desired, they should be specified separately by the purchaser, and suppliers should be consulted for availability.