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What is a Slump Test?

October 6th, 2023 | 1 min. read

By Legacy Engineering

slump test featured image

A slump test is a relatively quick and simple form of concrete testing. Click on the video below for a demonstration from one of Legacy's technicians.

slump test video

  1. A concrete sample is collected. The slump test is most accurate if the concrete in the sample is taken from the middle of the fresh concrete batch. Depending on how many yards of concrete you are using, it is best to test every 50 yards, to ensure the concrete will lay as intended. 
  2. A slump cone is placed on a slump board, the narrow side pointing up. 
  3. The cone is filled in three equal volumes. After filling to each height, the concrete is tamped 25 times. Once entirely filled, the top layer is evened and excess concrete is wiped off.
  4. Carefully, the cone is lifted vertically. Once the concrete completely slumps, the slump is measured by measuring the distance from the top of the concrete to the level of the top of the cone.


A concrete slump test measures fresh concrete consistency. Concrete can sometimes appear too wet or too dry which can be unfavorable for specific building conditions. While testing the workability, the slump test can also imply that the concrete you have purchased is poorly mixed. 

If your concrete is at a low slump (very dry) it is intended for pavement and roads because the concrete is designed for doing so. If the concrete is at a high slump (very wet) it is intended for reinforcing narrow spaces because of its ability to flow due to the amount of water in the mix. All concrete has a specified slump and it is important to consider that if the slump is outside of the defined range, it could cause concrete issues such as strength or separation, resulting in costing you more money.

Refer to the graphic to classify how your concrete could react to the test.

slump types

Determining the slump of your concrete can save you thousands if not hundreds of thousands of dollars. Testing before pouring is crucial to ensure that the concrete can withstand weathering conditions, and the building’s weight, and ensure that it is of expected quality.

At Legacy, our trusted technicians will test your concrete using their knowledge and accuracy. If you need to schedule concrete testing, please visit the CMT Scheduling page for further information!

Legacy Engineering