The block of Concrete or concrete block manufactured (shortened BBM) is a moulded element of masonry.

The block of Béton is usually and wrongly indicated by: “Breeze block”, “agglomerated”, “agglo”, “stud”, “plotet”, “Hardcore”, “quéron”, etc

Definition

It is a concrete block moulded, gray, in form of Parallélépipède used in construction. Its structure can be hollow or full according to its strength class. Indeed, more the concrete block will have of load to support, plus its strength class will be high, and more it will be heavy.

Strength classes sont :

  • B40: Resistance to 40  bars is 4 M Pa
  • B60: Resistance to 60  bars is 6 MPa
  • B80: Resistance to 80  bars is 8 MPa
  • B120: Resistance to 120  bars is 12 MPa
  • B160: Resistance to 160  bars is 16 MPa

Of regular form, solid, relatively light and little expensive, the concrete block is the component main thing of the external walls in the recent construction industries. It can be used only, in particular in the construction of hangars, surrounding walls. But generally for reasons of esthetics and insulation, one recovers it of another material, brick or Enduit coloured ( rough-cast ).

There exist blocks made up of Terra cotta or of Torchis but their use much rarer, or is limited to certain specific areas (ex: in Alsace, majority use of terra cotta bricks).

The breeze blocks are piled up the ones on the others by successive rows jointés between them thanks to a fine thickness of mortar in general 1,5 cm.

Their dimensions 20 cm height are generally, 50 cm length, their total thickness is variable. The most current thicknesses are 5 cm (planelle), 10 cm, 15 cm (partition), or 20 cm (190mm) (carrying outside).

There exist several types of concrete block:

  • current concrete blocks hollow
  • concrete blocks full (used mainly in infrastructure)
  • concrete blocks with angle (for vertical chainings)
  • concrete blocks in " U" (for horizontal chainings and lintels)

Manufacture of the concrete blocks

Factories blocks

The blocks are manufactured by factories, formed of a concrete batching and mixing plant and vibrating fixed presses. Important vibrations make it possible to decrease the quantity of cement in the concrete while preserving the same capacities.

Layers

Artisanalement, of the laying can be used for the manufacture of these blocks (full, hollow, hollow block, chainings, and blocks of any type… certain machines allow also the manufacture of car-blocking paving stones, of confined or edges and gutters). In fact mobile presses deposit the blocks on the ground by lines from 3 to 10 (according to dimensions of the blocks and the machine). This type of material ( manual or semi-automatic ) can be used in countries in voice of development because of its relatively weak cost, of its small overall dimensions which enable him to be easily moved on the spot of manufacture, but especially of the quality of the products returned compared with simple block-cement (containing mortar and not of concrete).

Manual moulds

Another artisanal method for manufacture of blocks or paving stones consists in using manual moulds; the product (concrete or mortar) is deposited on the ground by reversal of the mould. This method is obviously much more tiresome and the output is much less important. Moreover quality of the products is less compared to the layers which make it possible to manufacture regular blocks and better " compactés". This method can be improved by the use of a mobile plate .

Comparative of the productions

A press fixes manufactures on average 5 with 10  000 blocks per day, while the production by layer varies 1  000 with 3  500 blocks for the manual ones, and of 3 with 8  000 blocks for the semi-automatic ones.

Implementation

The necessary tools with the realization of a wall in concrete blocks are:

Notice

For the management of the motor vehicle traffic, concrete blocks of big size are sometimes used only. Their size can reach the cubic meter. They make obstacle with the passage or the parking.

Gallery

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