Which test is used to determine the consistency of concrete mixes?

The slump test is designed specifically to assess the consistency and workability of concrete mixes. This test measures how far a cone of concrete falls after being removed from an inverted position, allowing evaluators to determine how fluid or workable the concrete mixture is. A greater slump indicates a more fluid mix, while a smaller slump indicates a stiffer mix. This information is crucial for ensuring that the concrete has the right consistency for the intended application, such as ease of placement and compaction.

In contrast, the air content test measures the amount of air within the concrete mix, which is important for durability but not for consistency. The compression test evaluates the strength of cured concrete once it has set, looking at the maximum load it can withstand. The density test measures how much mass is contained in a given volume, which can give insights into the mix's composition but does not directly address the workability or consistency of the mix itself. Thus, the slump test is the definitive method for assessing the consistency of concrete mixes.