Slump Test | Procedure of Slump Test | Advantage of Slump Test | Disadvantage of Slump Test

Slump Test

Slump Test

  • The slump test is used to measure the workability of freshly made concrete. If concrete is made on the plant, a slump test is done on the plant itself.
  • Equipment for slump tests can be easily carried on site. No specialist is required for the slump test. Therefore slump test is used more.
  • The method of the slump test is simple and easy. Therefore slump test is used more in fieldwork.
  • According to IS code, the nominal aggregate size in fresh concrete in the slump test should not be more than 38 mm.
  • The slump test of each batch of concrete mixer can be prepared. During construction slump test is done to get uniform quality of concrete.
  • The water-cement ratio can be improved with a slump test.
  • The slump test gives good results for the workability of concrete with a 25 to 125 mm slump.

Apparatus of Slump Test

1. Slump Cone

The slump cone is mainly made of stainless steel. The diameter of the slump cone is as follows.

The slump cone has a top diameter of 10 cm and a bottom diameter of 20 cm. The height of the slump cone is kept at 30 cm.

Also Read: What Is Plum Concrete? | Plum Concrete Meaning | Plum Concrete Ratio

2. Temping Rod

The temping rod is made of stainless steel. The diameter of the temping rod is 16 mm.

3. Baseplate

The base plate is used for a smooth surface and level.

Procedure of Slump Test

  • First, take the slump cone and tamping rod to the place where the workability of the concrete is to be checked.
  • The inside surface of the slump cone is then cleaned. Oil is applied to the inner surface of the slump cone so that the concrete can slide comfortably into the slump cone.
  • The slump cone is then placed on a flat surface. The concrete is then filled layer-wise into the slump cone. Each level is pressed 25 times with a temping rod.
  • The top layer is finished with a towel after the concrete is filled up in the slump cone. Now the slump cone is slowly lifted upwards, so the concrete slowly settles down.
  • The distance between the surface of the slump cone and the surface of the concrete is called a slump.

Type of Slump

According to the Workability of Concrete, There Are Three Types of a Slump, Which Are as Follows.

1. True Slump

True Slump

A slump in which the variation is less, i.e., the same in all directions, is called a true slump.

2. Shear Slump

Shear Slump

If one-half of the concrete cone slides down, it is called a shear slump. The shear slump is measured as a difference in height between the height of the mold and the average value of subsidence.

If the sample shows a shear slump, the experiment shall be repeated. If in the repeated test also. The specimen shows a shear slump. The slump should be measured and recorded as a shear slump.

Shear slump indicates that the concrete is non-cohesive or harsh and shows the characteristic of segregation. This also indicates poor grading of aggregates.

3. Collapse Slump

Collapse Slump

If the concrete spreads with the slump cone in elevation, the slump will collapse slump Says. The slump is usually 25 to 75 mm for low workability, 50 to 100 mm for medium workability, and 100 to 150 mm for high workability.

Also Read: Density Of Cement, Sand, And Aggregate | What Is Density of Building Material | Density of RCC

4. Zero Slump

Zero Slump

This type of slump has zero difference in the slump test when the concrete mix is very hard. The workability of concrete from the same batch may vary.

Factors Affecting of Slump Test

The Factors Affecting of Slump Test Are as Follows.

  1. The ground should be level for the slump test. If the ground level is not level, then slump results are not correct.
  2. The slump test depends on the weather. As a result, it is not accurate in hot weather.
  3. Depending on the surface of the slump cone, if the surface inside the slump is rough, the result will not be true.
  4. Transport plays an important role in the slump test.
  5. Water cement ratio pan plays an important role in the slump test.

Advantage of Slump Test

Advantage of Slump Test

  1. The equipment for the slump test is light in weight.
  2. The method of the slump test is easy.
  3. The equipment of the slump test can be easily transferred.
  4. The slump test can be done both in the field and in the laboratory.
  5. The result of the slump test is obtained fast.
  6. Equipment for the slump test is cheap.
  7. Only one man is required for the slump test.
  8. The slump test gives good results for the workability of concrete with a 25 to 125 mm slump.
  9. A slump test is done to maintain the consistency of materials like aggregate, sand and admixture, etc.

Disadvantage of Slump Test

Disadvantage of Slump Test

  1. The slump test does not show workability for very wet and dry concrete.
  2. It does not give workability even in the concrete of hard mixing.
  3. The workability of the concrete in each batch varies.
  4. In this type of test, sufficient compaction should be done with the temping rod.
  5. Different results are obtained on the site and the plant.
  6. The surface of the base plate for the slump test should be free from vibration.
  7. Concrete should not be filled together in the slump test. It should be compacted about the level.
  8. Depending on the surface of the slump cone, if the surface inside the slump is rough, the result will not be true.
  9. The surface of the base plate for the slump test should be free from vibration.

Also Read: Type of Building Materials

Suggested Ranges of Workability of Concrete.

No Placing condition Degree of workability Slump(mm)
1 Pavement using a paver, building concrete, shallow foundation Very low 75-80
2 Mass concrete, beam, wall, column, strip footing, canal lining Low 25-75
3 Heavily reinforced section in-wall, slab, column, beam Medium 50-100
4 Slip formwork, pumped concrete Medium 75-100
5 Trench fill, in situ piling High 100-150
6 Tremie concrete Very high 100-175


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Frequently Asked Questions

What Is Slump Test?

The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete and, therefore, the ease with which concrete flows. It can also be used as an indicator of an improperly mixed batch.

What Does Slumped Mean?

The slump test is the most simple workability test for concrete, involves low cost, and provides immediate results.

What Is Slump Cone Test?

Gilson Slump Cones measure the workability of a fresh concrete mix in accordance with applicable ASTM and AASHTO standards. The slump cone test is performed for acceptance purposes, to record mixture characteristics, or as an indirect method of determining the water/cement ratio.

What Is a Good Slump for Concrete?

Most people in the business agree that a typical slump for ordinary decorative concrete applications would be in the 4- to 5-inch range, but there’s no hard-and-fast rule. “The slump should match the application,” says Daczko. “It could be anywhere from 1 to 10 inches depending on what you’re doing.

What Is a Concrete Slump Test?

A concrete slump test measures the consistency of a concrete batch to see how easily the concrete will flow. The test not only observes consistency between batches but also identifies defects in a mix, giving the operator a chance to amend the mix before it is poured on site.

What Happens If Concrete Slump Is Too High?

When there is too much water in the concrete, there is greater shrinkage with the possibility of more cracks and reduced compressive strength. As a general rule, every additional inch of slump decreases strength by approximately 500 psi.

What Is a Slump Test for Concrete?

The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete and, therefore, the ease with which concrete flows. It can also be used as an indicator of an improperly mixed batch.

What Is a Good Concrete Slump?

Explanation: According to IS 456-2000, the slump value (in mm) of the concrete used in ordinary RCC work for beams and slabs, etc., is 50 to 100 mm. For concrete work, low-workable concrete is preferred.

What Is a Slump Test in Concrete?

Concrete slump tester measures the consistency of a concrete batch to see how easily the concrete will flow. slump tester not only observes consistency between batches but also identifies defects in a mix, giving the operator a chance to amend the mix before it is poured on site.

Slump Test Is Used to Measure

Workability
The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete and, therefore, the ease with which concrete flows.

What Is the Slump Test for Concrete?

The concrete slump test measures the consistency of a concrete batch to see how easily the concrete will flow. The test not only observes consistency between batches but also identifies defects in a mix, giving the operator a chance to amend the mix before it is poured on site.

What Is the Maximum Concrete Slump?

Section 4.2. 2.2 states that the concrete shall have been proportioned to a slump of 2 inches to 4 inches before the HRWRA is added and allows a maximum slump of 8 inches at the point of delivery after the admixture is added to the concrete mixture.

What Is Concrete Slump?

The ‘slump’ of concrete refers to the consistency of fresh concrete before it sets – the higher the slump, the more fluid the concrete is. It’s a fairly confusing term for a complex-sounding process, but it really is quite simple when it all boils down.

How to Do Slump Test?

Place the filled cup upside-down on a flat, rigid surface. With your hands, carefully vibrate the cup in a steady lifting motion without stopping. Measure the distance of the slump with a ruler. The ideal slump should be about half the height of the plastic cup.

How to Measure Concrete Slump?

The slump of the concrete is measured by measuring the distance from the top of the slumped concrete to the level of the top of the slump cone.

How to Slump Test Concrete?

Fill the cup with freshly mixed concrete and pack it well. Place the filled cup upside-down on a flat, rigid surface. With your hands, carefully vibrate the cup in a steady lifting motion without stopping. Measure the distance of the slump with a ruler.

How to Perform Slump Test?

The mold is carefully lifted vertically upwards so as not to disturb the concrete cone. The concrete then slumps (subsidies). The slump of the concrete is measured by measuring the distance from the top of the slumped concrete to the level of the top of the slump cone.

How to Judge Concrete Slump?

The test involves filling a frustum of a cone in a specified way, removing the cone vertically, and measuring the distance that the concrete ‘slumps.’ The distance is defined as the slump height. The slump height must fall within a given range for the concrete to be acceptable.

How to Do Slump Cone Test?

Procedure for Concrete Slump Cone Test

Place the mold on a smooth horizontal non- porous base plate. Fill the mold with the prepared concrete mix in 4 approximately equal layers. Tamp each layer with 25 strokes of the rounded end of the tamping rod in a uniform manner over the cross-section of the mold.

How to Measure Slump Value?

In the case of a shear slump, the slump value is measured as the difference in height between the height of the mould and the average value of the subsidence.

How to Determine Slump of Concrete?

  1. Slump Cone Mold: The mold is 12-in. in height and known as an Abrams cone.
  2. Scoop: To place the concrete sample into the mouth of the cone.
  3. Steel Tamping Rod: This is a 5/8-in. Diameter, smooth-surfaced, 24-in. long rod with hemispherical (rounded) tips.
  4. Baseplate: Or some similar non-absorbent surface.
  5. Tape Measure: Or a ruler to record the test result.
  6. Sponge or Brush & Water: To dampen the cone and base before the test.

How Do You Measure Concrete Slump?

“Slump” is the distance, measured in inches, the concrete settles after the slump cone is removed. A concrete batch with a high slump indicates that the concrete has too much water in it and will likely be weak when fully cured. The ideal mix will not be too stiff or too soft but will have a slump of about 4″.

How to Perform a Slump Test on Concrete?

DIY Concrete Slump Test
Fill the cup with freshly mixed concrete and pack it well. Place the filled cup upside-down on a flat, rigid surface. With your hands, carefully vibrate the cup in a steady lifting motion without stopping. Measure the distance of the slump with a ruler.

How to Measure Slump?

  1. Clean the internal surface of the mold and apply oil.
  2. Place the mold on a smooth horizontal non- porous base plate.
  3. Fill the mold with the prepared concrete mix in 4 approximately equal layers.
  4. Tamp each layer with 25 strokes of the rounded end of the tamping rod in a uniform manner over the cross-section of the mold. For the subsequent layers, the tamping should penetrate into the underlying layer.

How to Check Slump of Concrete?

A concrete slump test measures the consistency of a concrete batch to see how easily the concrete will flow. The test not only observes consistency between batches but also identifies defects in a mix, giving the operator a chance to amend the mix before it is poured on site.

How to Do Slump Test of Concrete?

  1. Clean the internal surface of the mold and apply oil.
  2. Place the mold on a smooth horizontal non- porous base plate.
  3. Fill the mold with the prepared concrete mix in 4 approximately equal layers.
  4. Tamp each layer with 25 strokes of the rounded end of the tamping rod in a uniform manner over the cross-section of the mold. For the subsequent layers, the tamping should penetrate into the underlying layer.
  5. Remove the excess concrete and level the surface with a trowel.
  6. Clean away the mortar or water leaked out between the mould and the base plate.
  7. Raise the mould from the concrete immediately and slowly in the vertical direction.
  8. Measure the slump as the difference between the height of the mould and that of the height point of the specimen being tested.

How Much Slump Required in Concrete?

Unless otherwise permitted or specified, the concrete should be proportioned and produced to have a slump of 4 inches or less if it’s to be consolidated by vibration. If it’s consolidated any other way, the slump should be 5 inches or less.

How to Conduct Slump Test?

A slump is a form of mass wasting that occurs when a coherent mass of loosely consolidated materials or a rock layer moves a short distance down a slope. Movement is characterized by sliding along a concave-upward or planar surface.

How to Do the Slump Test?

The Slump Test is a neural tension test used to detect altered neurodynamics or neural tissue sensitivity.

Slump Test

The Slump test is really a variant of the SLR and the Lasègue’s tests performed in the seated position and is a progressive series of maneuvers designed to place the sciatic nerve roots under increasing tension.

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