Transport properties of self consolidating concrete

Consolidation Once the concrete is in place, it should be consolidated to remove large air voids developed during placement and to make sure that the concrete has flowed into all of the corners and nooks of the formwork.

The shear energy will only travel through a limited thickness of concrete, so when a thick concrete structures is being placed the fresh concrete is poured in layers, with each layer consolidated before the next is poured over it.

This can be as simple as pushing a wide blade over the fresh concrete surface to make it flat (screeding).

Floating and troweling is a process of compacting and smoothing the surface which is performed as the concrete is starting to harden.

What follows is a very brief summary of the most common process of making a concrete structure.

Much more information is available from other sources.

Mixing Mixing of concrete is a very important step for achieving good final properties, and one that can be quite difficult without the right equipment.

The lower the workability, the more mixing energy and mixing time is required.

Right: A concrete truck being filled with fresh premixed concrete.

(Images courtesy of the Portland Cement Association).

Finishing For concrete floors and pavements, the appearance, smoothness, and durability of the surface is particularly important.

Finishing refers to any final treatment of the concrete surface after it has been consolidated to achieve the desired properties.

For this reason it is not a good idea to completely separate the science of concrete from the more mundane process of making it.

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