What is the procedure for conducting a slump test?

The correct procedure for conducting a slump test involves filling the slump cone in three layers and measuring the height difference after the cone is removed. This method is critical for evaluating the workability or consistency of fresh concrete.

During the test, the slump cone, which has a specific height and diameter, is placed on a flat, non-absorbent surface. The concrete is then placed into the cone in three distinct layers, each layer being compacted to eliminate air pockets. After filling, the cone is lifted vertically, and the amount the concrete slumps or settles is measured from the top of the cone to the highest point of the concrete after the cone has been removed. This measurement is essential for assessing whether the concrete mix is suitable for its intended use, particularly in terms of ease of placement and finishing.

The other choices do not represent the slump test accurately. For example, mixing concrete and pouring it into a mold pertains to casting rather than measuring workability. Measuring buoyancy in water relates more to density and not the consistency of concrete. Lastly, vibrating concrete in a container and recording its density is focused on compaction rather than measuring slump, which specifically assesses the flow characteristics of fresh concrete.