What should be tested in concrete to guarantee its strength?

The slump test is a crucial method for assessing the consistency and workability of freshly mixed concrete, which directly relates to its performance and ultimately, its strength. This test measures how much the concrete mixture slumps when a cone-shaped mold is removed, giving an indication of its water-cement ratio. A lower slump can indicate a stiffer mix, which may achieve higher compressive strength, while a higher slump suggests a more fluid, workable mixture.

Quality control in concrete construction relies heavily on understanding and controlling the slump, as it affects the placement and finishing of the concrete and its ability to reach the desired strength. Although other factors such as density, durability, and color may provide some insights into concrete quality, the slump test specifically assesses the fresh concrete's properties that influence its ultimate strength and structural integrity. Therefore, it is a vital indicator in ensuring that the concrete will perform as expected in its intended application.