large concrete or cement masonry units for building
Concrete masonry unit Those that use cinders (fly ash or bottom ash) are called cinder blocks in North America, breeze blocks (breeze is a synonym of ash)[1] in the United Kingdom, and hollow blocks in the Philippines. In New Zealand they are known as concrete blocks or more commonly as just blocks. In Australia they are also known as Besser blocks or Besser bricks, because the American-based Besser Company was a major supplier of concrete-block-making machinery. 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.
Eiffel Tower Work on the foundations started on 28 January 1887.[15] Those for the east and south legs were straightforward, with each leg resting on four 2 m (6.6 ft) concrete slabs, one for each of the principal girders of each leg. The west and north legs, being closer to the river Seine, were more complicated: each slab needed two piles installed by using compressed-air caissons 15 m (49 ft) long and 6 m (20 ft) in diameter driven to a depth of 22 m (72 ft)[16] to support the concrete slabs, which were 6 m (20 ft) thick. Each of these slabs supported a block of limestone with an inclined top to bear a supporting shoe for the ironwork.