What process is used to remove air voids in concrete as it is placed?

The process of removing air voids in concrete as it is placed is known as consolidation. This is crucial because air pockets can weaken the concrete structure by reducing its overall strength and durability. Consolidation is typically achieved using techniques such as vibrating the concrete or using mechanical tools that help to compact the material, ensuring that it fills all void spaces and is well distributed within the formwork.

In contrast to consolidation, finishing refers to the processes employed to create the desired surface texture of the concrete after it has set to some extent. Posttensioning and pretensioning are methods used in constructing prestressed concrete. These techniques involve stressing tendons before or after the concrete has cured, but they do not specifically address the removal of air voids during the placement of concrete. Thus, consolidation is the correct process for achieving a dense and void-free concrete mixture right from the start.