Slump cone test:

  • Slump cone test for concrete, is the test performed on the fresh concrete to check the workability.
  • Slump test for concrete is done before the placing of concrete, so the quality of control is high as rejected mix can be discarded before pouring into the scaffolding or structural member. So, dismantling, repair of defective concrete members can be avoided.
  • The concrete slump test is used to measure the main property of concrete i.e. Workability or in other wods Consistency of fresh concrete.
  • The slump cone test measures consistency between batches and it maintain the consistency of concrete.
  • The test is most popular due to its use and it’s simplicity of procedure and simple apparatus.
  • Slump test for concrete doesn’t need any technical knowledge to conduct the test.

Why slump cone test performed on concrete

The reasons why slump cone test performed on concrete for quality control testing of concrete are,

  • Slump tests also checks the variation of construction materials in mix, mainly water-cement ratio.
  • Slump cone test is easy and fast to determine quality of concrete before poring into the moulds based on recommended slump values for the type of construction.
  • Slump cone test is most economical because it is done at site and does not require any laboratory or expensive testing machine.
  • Slump test for concrete doesn’t need any technical knowledge to conduct the test.
  • The test is most popular due to its use and it’s simplicity of procedure and simple apparatus.
  • Time requirement for test is less and not required large expenses.


The slump cone test result is the measurement of the behavior of a compacted inverted cone of concrete under the action of gravity. It measures the consistency or the wetness of concrete.


  • Slump cone apparatus
  • Scale for measurement
  • Temping steel rod – 16 diameter & 600 mm long
Slump cone apparatus

Procedure of Slump cone test for concrete :

  1. The mould for the slump cone test is a hollow frustum of a cone, 300mm of height, dia. 200mm at and dia. 100mm at top as shown in figure. .
  2. The base is firstly placed on smoothe surface and then the container is filled with concrete in 3 layers ( concrete whose workability is to be test)
  3. Each layer should be uniformly temped 25 times with a standard 600mm long 16mm dia. steel rod, rounded at the end.
  4. When the mould is completely filled with concrete, the top surface is leveled (leveled with mould top
    opening) by means of screening and rolling motion of the temping rod.
  5. The mould must be firmly held against its base during the entire operation ,so that it could not move due to the pouring of concrete and this can be done by means of handles or foot – rests brazed to the mould.
  6. Immediately (within 5 – 10 seconds) after filling is completed and the concrete is leveled, the cone is slowly and carefully lifted vertically – An  unsupported concrete will now slump.
  7. The decrease in the height of the center of the slumped concrete is called Slump.
  8. The slump is measured by placing the cone just besides the slump concrete and the temping rod is placed over the cone so that it should also come over the area of slumped concrete.
  9. The decrease in height of concrete to that of mould is noted with scale, usually measured to the nearest 5mm
Slump cone apparatus
Slump cone apparatus


  • All the apparatus should be moistened at the beginning of the test to reduce the slimp fall due to friction.
  • All the apparatus should be clean and neat at the starting of test.

Types of Slumps:

The slumped concrete takes various shapes, and according to the profile of slumped concrete, the slump is termed as;

Type of slumpRangeUse
True SlumpCorrect slumpThis concrete will be adopted for use & also for further tests
Zero SlumpDry RangeConcrete not workable (No variation can be detected between mixes)
Collapsed SlumpConcrete is too wetSlump test not appropriate
Shear SlumpInvalidTemping not uniform – Fresh sample to be taken – Test repeated

Applications of Slump Test:

The applications of slump test is as follows,

  1. Slump test is used to maintain the quality of the concrete for different batches created at different time and conditions on site.
  2. Slump cone test is very important to check the quality and variation due to time.

Interpretation of results:

Slum (mm)Degree of workabilityUse for which concrete is suitable
0-25Very lowVery dry mix – Used in road making, vibrated by power operated machines.
25-50LowLow workability mix – Used for foundations with light reinforcement, Roads vibrated by hand operated machines.
50-100MediumMedium workability mix – Manually compacted flat slabs. Normal reinforced concrete manually compacted and heavily reinforced sections
100-175HighHigh workability concrete – For sections with congested reinforcement. Not normally suitable for vibration.

Result of slump cone test:

The result of slump cone test is interpritated on slump height, some of the major key points for result of slump cone test is as follows,

  • An increase in slump may mean, for instance, that the moisture content of aggregate has unexpectedly increased. Other cause would be a change in the grading of the aggregate, such as a deficiency of sand.
  • Too high or too low a slump gives immediate warning and enables the mixer operator to remedy the situation.
  • This application of slump test as well as its simplicity is responsible for its widespread use.


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