Workability of Concrete by Slump Cone Test (IS-1199-1959)

Slump Test

A slump test is conducted on-site to assess the workability and consistency of fresh concrete. While not providing precise results, it is beneficial for identifying the uniformity of the concrete mix.

Slump Test of Concrete

We will be performing tests on a wide range of materials in the field. These tests lack precision and do not offer high levels of accuracy. The slump test is no different.

Object of Slump Test

The purpose of this test is to evaluate the uniformity or ease of handling of recently mixed concrete, with aggregate sizes not exceeding 38 mm, through the use of a slump test device.

What is meant by the slump cone test?

The slump test is conducted on-site to assess the workability and consistency of the fresh concrete. While it may not provide precise results, it is valuable for identifying the uniformity of the concrete mix.


Equipment’s used for Slump Test

  • Trowel
  • Tamping Rod – ( 60 cm length )
  • Measurement Scale
  • Smooth Surface Pan
  • Slump Cone

Dimensions of Slump Cone Dimensions

Height – 30 cm
Top Diameter – 10 cm
Bottom Diameter – 20 cm
Dia of the Tamping rod – 16mm

Test Procedure

  1. Begin by positioning the slump cone mould on the smooth surface pan, then proceed to layer the fresh concrete up to the top of the slump cone mould.
  2. Use the tamping rod to tamp each layer of concrete up to 25 times.
  3. Fill the concrete up to the top of the cone.
  4. Level the concrete and remove any excess from the top.
  5. Carefully lift the cone mould vertically to allow the concrete to fall onto the pan.
  6. Measure the difference between the height of the slump cone mould and the concrete subsidence to determine the slump value in millimeters.

Types of Slump

  1. True Slump occurs when the concrete slides down after the slump cone mould is removed, maintaining the shape of the mould.
  2. Shear Slump happens when half of the concrete slides down on the pan after the removal of the slump cone mould, requiring a retest.
  3. Collapsed Slump is when the concrete falls completely on the pan after the removal of the slump cone mould, making it unsuitable for pouring.

Recommended Slump:

There are no strict rules that must be followed for various types of construction projects.

Instead, recommendations for slump values have been made based on past experiences.

It is important to note that these recommendations should be viewed as general guidelines rather than mandatory criteria.

What is a zero slump concrete?

The condition where the concrete does not slump after the removal of the mold is referred to as zero slump. This indicates that the concrete mixture was overly rigid and had a lower water-cement ratio.

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