What conclusions we can get from slump test? What are the limitations of Slump test?

The slump test measures the resulting behavior of a compacted inverted cone of concrete under the action of gravity. It indicates consistency or wetness of concrete , for the Limitations there is not direct relationship between workability and the value of slump and it is not suitable for concrete in which maximum size of aggregate exceeds 40 mm , and it is working only in plastic mixes, it will not occur in case of dry mixes.

The slump test measures the consistency of the concrete and indicates about the variation in the ingredients. 

Slump test limitations could vary from zero slump to free flowing depending on the mix design and intended use of the concrete.

Workability of concrete is the result for Slump test. Slump value for various concrete activities are follows:1. Concrete for road construction = 20 to 40 mm  2. Concrete for tops of curbs, parapets, piers, slabs and wall = 40 to 50 mm 3. Concrete for canal lining = 70 to 80 mm 4. Normal RCC work = 80 to 150 mm 5. Mass concrete = 20 to 50 mm 6. Concrete to be vibrated = 10 to 25 mm

Slump is a measurement of concrete's workability

Thank you for your question. It is  related to the Concrete material/ out of my specialty.

slump test to be used for inshort

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. The test is popular due to the simplicity of apparatus used and simple procedure. The slump test is used to ensure uniformity for different loads of concrete under field conditions.A separate test, known as the flow table, or slump-flow, test, is used for concrete that is too fluid (workable) to be measured using the standard slump test, because the concrete will not retain its shape when the cone is removed.The test is carried out using a metal mould in the shape of a conical frustum known as a slump cone or Abrams cone, that is open at both ends and has attached handles. The tool typically has an internal diameter of 100 millimetres (3.9 in) at the top and of 200 millimetres (7.9 in) at the bottom with a height of 305 millimetres (12.0 in).The cone is placed on a hard non-absorbent surface. This cone is filled with fresh concrete in three stages. Each time, each layer is tamped 25 times with a 2 ft (600 mm)-long bullet-nosed metal rod measuring 

5/8 in (16 mm) in diameter.[2] At the end of the third stage, the concrete is struck off flush with the top of the mould. The mould is carefully lifted vertically upwards, so as not to disturb the concrete cone.

The concrete then slumps (subsides). 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

Concrete slump test measures the consistency of fresh concrete before it adjusts.

to check the water content for its workability

Slump is a measure of Concrete's work-ability.. it's value is measured in inches or centimeters.. most preferred value range is 3-4 inches or 6-9 cms..