Concrete slump Cone Test | Appaturas | Procedure
Concrete Slump Cone Test
The concrete slump cone test measures the consistency of fresh concrete before it sets. It is performed to verify the workability of freshly made concrete and, therefore, the ease with which the concrete flows.
It can also be used as an indicator of an incorrectly mixed batch. The test is popular due to the simplicity of the apparatus used and the simple procedure. The slump test is used to ensure uniformity of different concrete loads under field conditions.
A separate test, known as the flow chart, or slump flow test, is used for concrete that is too fluid (not workable) to be measured using the standard slump test, because the concrete will not retain its shape when the cone It is removed.
Concrete Slump Cone Test Apparatus and Procedure
The inner surface of the mold is thoroughly cleaned and freed from the superfluous. moisture and adhesion of any old set concrete before testing begins.
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| Damping Rod ,Slump Cone set |
The mold is placed on a smooth, horizontal, rigid and non-absorbent surface.
The mold is filled in four layers, each approximately 1/4 the height of the mold.
Each layer is rammed 25 times with a rod taking care to distribute the strokes evenly over the
cross section. After the top layer has been rolled, the concrete is leveled with a Paddle and tamping rod.
The mold is removed from the concrete immediately by slowly and carefully lifting it a vertical direction.
This allows the concrete to sink. This subsidence is known as a concrete settlement.
The difference in level between the height of the mold and that of the highest point of Sunken concrete is measured. This height difference in mm is taken as a drop of concrete.
The settlement pattern indicates the characteristics of the concrete in addition to the settlement.
value. If the concrete collapses evenly, it is called true sinking. If one of the cones slides down is called shear drop.
In the case of a shear depression, the value of the depression is measured as the difference in height between the height of the mold and the average value of the sinking.
Slump Cone Test Result
The slumped concrete takes different shapes and as indicated by the profile of slumped concrete, the slump is named as true slump, shear slump or collapse slump.
In the event that a shear or collapse slump is accomplished, a new example ought to be taken and the test rehashed.
Just a true slump is of any utilization in the test. A collapse slump will commonly imply that the blend is excessively wet or that it is a high usefulness blend, for which the slump test isn't proper.
Extremely dry blends having slump 0 – 25 mm are ordinarily utilized in street making, low functionality blends having slump 10 – 40 mm are regularly utilized for establishments with light support, medium usefulness blends in with slump 50 – 90 mm, are commonly utilized for ordinary strengthened concrete put with vibration, high functionality concrete with slump > 100 mm is normally utilized where fortifying has tight dispersing, as well as the concrete needs to stream a significant stretch.