Red Seal Concrete Finisher Practice Exam

What does the term "slump" refer to in concrete?

1. The thickness of the mix

2. The measurement of the workability or fluidity of the concrete mix

3. The temperature of the concrete

4. The setting time of the concrete

The correct answer is: The measurement of the workability or fluidity of the concrete mix

The term "slump" in concrete specifically refers to the measurement of the workability or fluidity of the concrete mix. It is a crucial parameter used by concrete finishers and contractors to understand how easily the concrete can be placed and finished. The slump test is performed by filling a specific cone-shaped mold with fresh concrete and then lifting the cone off, allowing the concrete to settle. The distance that the concrete slumps or sinks is recorded, providing an indication of its consistency. A higher slump generally indicates a wetter, more fluid mix, making it easier to work with, while a lower slump suggests a drier mix that may be harder to place and finish. Understanding slump is essential because it affects how the concrete will perform during placement, potential segregation of aggregates, and the final surface finish. An appropriate slump value ensures that the concrete will hold its structural integrity while being workable enough for the intended application.