Usefulness of Slump Test On Concrete

Purpose of Test
Slump test is initiated to evaluate the conformity of concrete mix. Generally it is undertaken to verify either the adaptability of concrete mix is up to the standard or not.

Tools Utilized
. Slump Cone
. Tamping Rod
. Spatula
. Brush

Process

1. At first clean the Cone with a brush or some water. Ensure that the cone is not drenched or fully dry as it may cause changing mix water content.
2. The cone is arranged on a hard surface and it is necessary to grasp the cone firmly by the operator.

3. Concrete is poured in three layers maintaining nearly identical height. All layers must be tamped 25 times with the use of tamping rod.
4. When cone is packed up, unnecessary concrete is taken with a spatula.
5. Cone is then elevated upright lightly. Proper care should be maintained while elevating because tilting can result in modifying the slump.

Measurement:
Slump is then gauged instantly by measuring the variance amid original cone height and specimen height.

Slump Characterization:
Besides, focusing on applicability, Slump test demonstrates other mix properties like segregation resistance, cohesiveness.

Slump can bear various shapes and on the basis of shapes, slump becomes perfect slump, shear slump or collapsed slump.

If collapsed or shear slump is attained than test is reiterated to ensure that results are perfect. Collapsed slump indicates that mix is too wet or it is high workability mix as a provision against self-compacting concrete. For that purpose, this test offers no value. So, other tests like flow test, V-funnel test or J-ring test should be carried out which are intended for high workability mix.

View Source

Image Courtesy: constructionsite.pk