What is the consequence of entrapped air in fresh mixed wet cast concrete?

Entrapped air in fresh mixed wet cast concrete can significantly impact its overall quality and performance. When air gets trapped in the concrete mix, it can lead to an increase in the volume of voids within the material. This void formation can, in fact, represent a considerable percentage of the total volume of the mix—up to 20 percent in some cases.

This high level of entrapped air can cause problems, such as reducing the strength and density of the concrete, leading to a lower quality final product. It can also affect the curing process and the overall durability of the concrete once it sets. Understanding the correct management of air content in concrete is crucial for achieving optimal results in concrete work, particularly in applications where strength and durability are essential.

While entrapped air might seem beneficial in certain contexts—such as when it can increase workability or enhance finish quality—it typically does not improve durability and should be carefully controlled. Therefore, recognizing and addressing entrapped air is vital for any concrete manufacturer to ensure the structural integrity and longevity of their products.