Each percentage of entrained air in the concrete mixture will increase the absolute water volume by how much?

The correct answer indicates that for each percentage of entrained air in a concrete mixture, the absolute water volume increases by 0.27 cubic feet per cubic yard. This information is important because it emphasizes the relationship between the air content in the mix and the necessary adjustments to water volume, which is crucial for achieving the desired workability and strength.

In concrete mixes, entrained air is intentionally introduced to improve the durability and performance of the concrete, especially in freeze-thaw environments. However, this addition of air increases the volume of the mix, leading to a reduction in the density of the mix. Consequently, to maintain the proper water-to-cement ratio and ensure that hydration occurs effectively, the absolute water volume must be adjusted. The value of 0.27 cubic feet per cubic yard represents a standardized measurement used in practice to guide concrete mix adjustments for optimal performance.

Understanding this adjustment helps concrete inspectors and engineers create mixes that meet specified requirements and ensure the long-term performance of structures.