Hollow Block

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Hollow Block

By | October 2010
Page 1 of 3
Concrete masonry unit
From Wikipedia, the free encyclopedia

A stack of rectangular CMUs
"Cinder block" redirects here. For the American singer, see Cinder Block (musician). In the United States, a concrete masonry unit (CMU) — also called concrete block, cement block or foundation block — is a large rectangular brick used in construction. Concrete blocks are made from cast concrete, i.e. Portland cement and aggregate, usually sand and fine gravel for high-density blocks. Lower density blocks may use industrial wastes as an aggregate. Those that use cinders (fly ash or bottom ash) are called cinder blocks in the US, breeze blocks (breeze is a synonym of ash)[1] in the UK and are also known as besser blocks or bricks in Australia. Clinker blocks use clinker as aggregate. In non-technical usage, the terms 'cinder block' and 'breeze block' are often generalized to cover all of these varieties. Lightweight blocks can also be produced using aerated concrete. Contents [hide]

1 Sizes and structure
2 Uses
3 Gallery
4 See also
5 References
6 External links
[edit]Sizes and structure

Concrete blocks may be produced with hollow centres to reduce weight or improve insulation. The use of blockwork allows structures to be built in the traditional masonry style with layers (or courses) of overlapping blocks. Blocks come in many sizes. In the US, the most common size is 8 in × 8 in × 16 in (20 cm × 20 cm × 41 cm); the actual size is usually about 3/8 in (1 cm) smaller to allow for mortar joints. In Ireland and the UK, blocks are usually 440 mm × 215 mm × 100 mm excluding mortar joints (approximately 17.3 in × 8.5 in × 3.9 in). [edit]Uses

Concrete block, when reinforced with concrete columns and tie beams, is a very common building material for the load-bearing walls of buildings, in what is termed "concrete block structure" (CBS) construction. American suburban houses typically employ a concrete foundation and slab with a concrete block wall on the perimeter....