Slump Test Apparatus - MSS Engineering

Slump testing equipment is used to evaluate the fresh concrete's consistency and workability and by extension, the concrete mix's water/cement ratio.

A laboratory or on-site slump test is used to evaluate the fluidity of concrete. A concrete slump test results can provide insight into how consistent individual batches are. The concrete's workability and quality can be gleaned from the shape of the slumps. A few tamps or blows with a tapping rod on the base plate can also be used to judge the features of concrete about the tendency of segregation. This test's straightforward slump test apparatus and protocol have ensured its continued use since its introduction in 1922.

The setup will include a mild steel sheet slump cone with carrying handles, a chrome-plated steel tamping rod that is 16 mm in diameter and 600 mm in length and is rounded off at one end, and a steel base plate with markings for measurements.

Slump Test Apparatus

1) MOULD:

The test specimen's mould will be shaped like the frustum of a cone, and its interior will be these dimensions:

• Total Depth: 20cm Bottom Diameter:
• Maximum outer circumference, 10cm.
• Length: 30cm

Both the top and bottom of the mould shall be open and perpendicular to the axis of the cone, and the metal used to make it will be at least 1.6 mm (16 SWG) thick. The interior of the mould will be completely flat and smooth. Fitting foot pieces to a base plate and handles will allow for vertical lifting away from the moulded concrete test specimen. The mould will come equipped with a suitable guiding attachment. Cleats and a swivel handle will be included with the unit.

2) ROD FOR TAMPING

The tamping rod will be 60 centimetres long, steel, 16 millimetres in diameter, and rounded at one end.

Procedure of Slump test 

Slump is documented as the amount of the specimen's subsidence in millimetres. If a slump specimen breaks apart or shears off laterally during testing, the results will be inaccurate, and the test will need to be redone again, if the specimen shears in the second test, the slump and the specimen sheared must be recorded.

The following procedures are carried out during a Slump test:

• The first step is to ensure that the mould’s inside surface is dry, dust- and moisture-free, and devoid of any previously used concrete.
• The mould must be placed on a flat, stiff, non-absorbent surface.
• After the mould has been prepared, four layers of fresh concrete are placed within, taped individually 25 times with a taping rod, and the top surface is levelled with a trowel.
• After that, the mould is carefully lowered vertically and lifted from the concrete cone.
• As a result of gravity's pull, this loose concrete causes the entire surface to sink.
• A SLUMP of concrete describes the peripheral subsidence seen in some areas.
• The "slump value of concrete" is the difference in millimetres between the height of the concrete after it has settled and the height of the mould cone.