Slump Test of Concrete
Slump tEST (IS:1199-1959)
OBJECTIVe
To determine the workability or consistency of concrete mix of
given proportion by slump test.
REFERENCE STANDARDS
IS : 1199-1959 – Methods of tests for Slump of concrete.
EQUIPMENT
& APPARATUS
§ Slump Cone with base plate
§ Tampering Rod
PROCEDURE
- Take the sample concrete from the discharge
location.
- The internal surface of the slump cone is to
be thoroughly cleaned and placed on a smooth, horizontal, rigid and non
absorbent surface.
- Place the mixed concrete in the cleaned slump
cone in 4 layers each approximately 1/4 in height of the mould. Tamp each
layer 25 times with tamping rod.
- Remove the cone immediately, rising it slowly
and carefully in the vertical direction.
- As soon as the concrete settlement comes to a
stop, measure the subsistence of the concrete in cms, which gives the
slump.
SAFETY
& PRECAUTIONS
- The strokes are to be
uniformly applied through the entire area of the concrete section.
- The cone should be removed
very slowly by lifting it upwards without disturbing the concrete.
- During filling the mould
must be firmly pressed against the base.
- Vibrations from nearly
machinery might also increase subsidence; hence test should be made beyond
the range of ground vibrations.
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