IV.

Concrete Masonry

Concrete masonry is block and brick building units molded of concrete and used in all types of masonry construction. Concrete masonry is used for load-bearing and nonload-bearing walls; piers; partitions; fire walls; backup for walls of brick, stone, and stucco facing materials; fireproofing over steel structural members; firesafe walls around stairwells, elevators, and other enclosures; retaining walls and garden walls; chimneys and fireplaces; concrete floors; and many other purposes.

About 60 percent of all concrete masonry units, such as cinder blocks, are made with lightweight aggregates. Processed clays, blast-furnace slag, shales, natural volcanic aggregates, and cinders are the lightweight aggregates most commonly used. The size of the masonry unit most commonly used for walls, both below and above ground, is 20 by 20 by 40 cm (8 by 8 by 16 in). Masonry units are laid horizontally, and are cored to reduce weight and to provide an insulating air space within the block. New types of concrete masonry, such as split and slump block, are being used as facing in homes, commercial buildings, schools, churches, and municipal facilities.

Basic block types are fairly well standardized today. Specific types can usually be supplied for any construction without cutting or fitting. Special molds are available for the production of patterned shadow effects on exterior and interior block walls. It is possible to supply virtually any color or type of texture.