Blocks
Precast concrete components

Blocks and other masonry products, as well as floor joists, are always manufactured using immediate demolding with vibrating presses.

These machines, which used to be mobile, are now mostly stationary. They use the same principle as the first machines from the 1920s. This involves filling a metal mold with "dry" concrete, then compacting it using a combination of vibration and compression.

Regardless of the type of machine, the operating cycle is as follows (Figure 1 ).

• The mold, whose base consists of a wooden or metal board, is filled with concrete using a movable drawer.

• The concrete contained in the mold is compacted by vibration and then compressed by a rammer.