Concrete Slump Cone Test

Neenu June 19, 2020
Slump Value of Fresh Concrete Measurement

The slump test is performed to measure the workability and  consistency of the concrete. In other words, it studies the ability of concrete to flow. It is the most well known quality test conducted to concrete to characterize the workability of concrete.

 Watch the Video: How to Perform Concrete Slump Cone Test at Site?


The slump test is an inexpensive and rapid test followed in construction site to determine whether the fresh concrete manufactured in batches are of good or bad quality. 

The slump test is standardized widely throughout the world. The main standard codes for slump test are ASTM C143 for United Kingdom and EN 12350 in Europe. All other codes are developed based on these standards and their respective country conditions.


Concrete Slump Cone Test Apparatus

Slump Cone Test of Fresh Concrete - Materials Required:
  1. Slump Cone or Frustum of a Concrete
  2. Fresh Concrete Mix
  3. A measuring scale or ruler
  4. Tamping Rod
Concrete Slump Cone Test Apparatus
Concrete Slump Cone Test Apparatus


The test apparatus consist of a mould in the shape of a frustum of a cone. The base diameter of the cone is 8 inches, diameter is 4 inches and height is 12 inches. In Indian Standard Codes, the slump height is 30cm, top and bottom diameters are 10 and 20 cm respectively. 

Concrete Slump Cone Test Procedure - Tips for Proper Slump Testing

The slump test are sensitive that is encountered within the test procedure given by ASTM C 143. If different technicians measure the sample and give different slump values varying as much as 1 inches for the same concrete, it is something that must be corrected. Hence careful observation on the testing procedures can help minimize the variations.
The slump cone test procedures include:

Slump Cone Test Preparation

  1. Clean the slump cone mold and dampen it before the test.
  2. The test is performed on a base that is level, moist, non-absorbent and rigid.
  3. Do not perform the concrete slump test on a plywood base. If it is unavoidable, place a metal sheet over the wood base or conduct the test over a premanufactured metal base.
  4. Do not conduct the test on the tailgate of a pickup truck.

Slump Cone Test Procedure



  1. Conduct the test near to the availability of the fresh concrete.
  2. After arranging the cone on the rigid base, start adding fresh concrete into it.
  3. The mold must be filled in three layers of concrete in equal volume. So you must take concrete of one-third volume of cone during each layer.
  4. After adding each layer, it is compacted with 25 strokes using a tamping rod.
  5. After completely filling chip off excess concrete and level the top of the cone.
  6. Move the mold vertically upwards within 3 to 7 seconds. Avoid any sort of twisting or jerking motion during the procedure.
  7. Always conduct the test within 2 and half minute to avoid any sort of slump loss.

Concrete Slump Cone Test Procedure
           Concrete Slump Cone Test Procedure


Slump Value of Fresh Concrete Measurement

Slump value is the difference between the height of the slump cone and the height of the settled Concrete as shown in figure below.


Measuring Slump Value of Concrete
Measuring Slump Value of Concrete

Different Slump Value for Concrete Slump Test


After conducting slump test, there are mainly 4 types of slump possible to occur, as shown in figure below. They are:
  1. True Slump
  2. Shear Slump
  3. Collapse Slump
  4. Zero Slump

Different Slump Value for Concrete Slump Test
Different Slump Value for Concrete Slump Test

What is True Slump in Fresh Concrete?

True slump of concrete is the shape of concrete formed by standing intact with a symmetry in the shape, after removing the slump cone vertically upwards. This the only type of slump that is accepted as per ASTM C143. It is subsidence of a normal concrete mix without breaking up.

What is Zero slump and collapsed Slump in Fresh Concrete?

Zero slump and collapsed Slump is the slump formed when the concrete collapses completely, outside the range of workability required. Collapsed slump is an indication of concrete mix that is very wet. Zero slump is observed in very harsh mix.

What is Shear Slump in Fresh Concrete?

Shear slump is the concrete texture formed due to cohesion less mix or harsh mix. A mix showing shear slump has to be tested once more with a different sample. Even after the second test, the mix shows shear slump, then the mix must be rejected.

Suitability of Slump Test on Fresh Concrete

  • The slump cone test on concrete is not ideal for a mix with coarse aggregates size greater than 1.5 inches.
  • The particles greater than 1.5 inches in size must be removed by wet sieving.
  • The tapping with tamping rod can show different behavior even if they have same slump.
  • A harsh concrete with few amounts of fines has a tendency to fall apart when tapped. This is only used for pavement application or for mass concreting.
  • A concrete very cohesive in nature when tapped can be used for difficult placement.
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