ASTM C 90 - 05 Standard Specification for Loadbearing Concrete Masonry Units

American Society for Testing and Materials (ASTM). Current edition approved Feb. l. 2005. Published April 2005. Originally approved in 1931. Last previous edition approved in 2003 as C 90-03. 4 p. This specification covers hollow and solid concrete masonry units made from hydraulic cement, water, and mineral aggregates with or without the inclusion of other materials. There are three classes of concrete masonry units: normal weight, medium weight, and lightweight. These units are suitable for both loadbearing and nonloadbearing applications.