This National Standard applies to concrete masonry units which are manufactured from hydraulic cement, water and mineral aggregates.
NOTE 1: This standard is based on ASTM C90, Standard Specification for Loadbearing Concrete Masonry Units.
NOTE 2: This standard does not apply to autoclaved aerated concrete masonry units. Included are compulsory requirements for surface finish, face shell thickness, web thickness, oven dry density, maximum water absorption, compressive strength and marking.
This standard also outlines the mechanism to demonstrate compliance to these requirements and includes measures to be taken in the event of non-compliance.