Concrete block

Description

A masonry construction element. The concrete block was patented in 1855 but was not mass produced until a block machine was made in 1900. Concrete blocks are commonly manufactured with portland cement and aggregates. By 1924, the industry standardized the block size to 8 x 8 x 16 inches with 1-3 hollow cores. They are very durable, have high compressive strength and are fire-resistant. Lightweight aggregates, such as cinders, slag, shale and clay were used to decrease the block weight as well as to incorporate air into the mixture. Early block machines produced a variety of decorative surfaces, such as cobblestone, brick, ashlar and rockface. Concrete blocks were used for the construction of basements, foundations, chimneys, and entire homes in the early 1900s. Blocks with a glazed enamel surface were used used as decorative interior finish walls in many schools and public buildings.

Synonyms and Related Terms

bloc de béton (Fr.); bloco de betão (Port.); glazed brick; screen block; Unit block; cinder block; building block; artificial stone; concrete tile;

Brand names: Boyd block; Casberg block; Hydrostone; CeloCelocrete; Forster block; Haydite; Compostone; Miami stone; Pottsco; Straublox; Textile block; Waylite

Risks

• Water infiltration and salt accumulation may cause efflorescence and spalling.

Resources and Citations

• P. Simpson, H. Hunderman, D. Slaton, "Concrete Block", in Twentieth-Century Building Materials, T. Jester (ed.), McGraw-Hill: New York, 1995.

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

• Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996