Advertise with us
Estimating Sheet

How To Do A Concrete Slump Test

Construction Software

The objective of the concrete slump test is to find out the workability of concrete. Concrete is considered as workable when it contains sound strength.

Workability of Concrete: Workability refers to a composite property of concrete that defines how effortlessly freshly mixed concrete is combined, placed, consolidated, and finished with nominal loss of uniformity. Workability is affected by the quantity of water, aggregate grade and percentage of fine materials in the mix.

To determine the workability of concrete, the following tests are normally conducted.

Test 1. Slump test
Test 2. Compaction factor test
Test 3. Flow test
Test 4. Kelly ball test
Test 5. Vee-Bee consistometer test.
Test 6. K-Slump Test

Concrete Slump Cone Test or Slump Cone Test of Concrete

The prime objective of the concrete slump test or slump cone test is to find out the workability or uniformity of concrete mix produced at the laboratory or the construction site all through the advancement of the work. A concrete slump test is performed from batch to batch to verify the homogeneous quality of concrete throughout the construction.

Normally, the workability is determined with the concrete slump value, that specifies water-cement ratio, but there are also several other factors that range from properties of materials, mixing methods, dosage, admixtures etc. to impact the concrete slump value.

The concrete slump test is not recommended for very wet or very dry concrete.

This test is applied as a control test and demonstrates the consistency of concrete from batch to batch. Repeated batches of a similar mix, provided to the same slump, will contain the same water content and water-cement ratio, weights of aggregate, cement, and admixtures are consistent and aggregate grading remains within reasonable limits.

Also Read: How to validate the compressive strength of the concrete cube at jobsite

Tools Used for Slump Test of Concrete

The necessary apparatus range from Mettalic Mould that is in the shape of frustum cone, A tamping rod containing bullet end, Scale or tape for measuring the slump. Metallic sheet for arranging Slump and trowel for pouring concrete in the slump.

The mold for the test remains in the form of the frustum of a cone with height 30 cm, bottom diameter 20 cm and top diameter 10 cm. The tamping rod should be made of steel with 16 mm diameter and 60cm length and rounded at one end.

a. Metallic Mould
b. Tamping Rod
c. Scale / Tape
d. Metallic Sheet
e. Trowel

Method of Concrete Slump Cone Test

First Step - Cleanse the inside surface of Frustum cone properly and it does not contain any moisture content and adherence of any old set concrete.

Second Step - Then arrange the Mould (Cone) on the metallic steel plate or on any smooth surface.

Third Step - Place the concrete in four layers each to fill up the cone keeping a fairly accurate height of 1/4th of the mold.

Fourth Step - Use the tamping rod to tamp every layer 25 times with the purpose of allocating the strokes equally over the cross-section.

Fifth Step - Once the 4th layer is filled up, the concrete is removed with the trowel.

Sixth Step - The mold is detached from the concrete instantly in a vertical direction by lifting it gradually with care.

Final Step - It facilitates the concrete to subside. This subsidence is known as a SLUMP.

How To Do A Concrete Slump Test