What's Considered a Concrete Masonry Unit?
1. Materials used in manufacturing
Only units made with “dry-cast concrete” are assessed.
Masonry units made with other materials like clay, adobe, pressed wood, etc. are excluded.
Dry-Cast
Dry-cast concrete means a composite material that is composed essentially of aggregates embedded in a binding medium composed of a mixture of cementitious materials (including hydraulic cement, pozzolans, or other cementitious materials) and water of such a consistency to maintain its shape after forming in a block machine.
2. Method of Manufacturing
Only units made on a mechanized equipment such as a block machine that utilizes vibration and compaction to form the product are assessed.
Units made with wet-cast concrete (precast), units made by compacting materials by hand in a mold, and other variations, are excluded
Block Machine
Block machine means a piece of equipment that utilizes vibration and compaction to form concrete masonry products.
3. Purpose of unit
Only units manufactured for use in masonry construction are included. “Masonry” means a built-up construction or combination of building units bonded together with or without mortar, grout or other accepetd methods of joining.
Examples of excluded units include concrete brick made specifically for utility purposes, hardscape units for pavements, and retaining walls.
Concrete Masonry Unit
Masonry unit means a noncombustible building product intended to be laid by hand or joined using mortar, grout, surface bonding, post-tensioning or some combination of these methods.
4. Size of unit
Only units with an actual width (or bed depth) of 3 inches or greater are included.
An example of an excluded unit would be thin adhered masonry veneers.
Size
The dimensions of a concrete masonry unit are stated in this order - width, height, and length (WHL)