The SLUMP test shows the workability of concrete. Workability
measures how easy the concrete is to place, handle and compact.
Or
slump test is a measure of the consistency of the concrete. The
consistency therefore is a measure of the water content of the concrete. The
water content controls and affects the cement content of the concrete. Since
the slump test is important, do not substitute a guess for an actual test.
The
slump test is done to make sure a concrete mix is workable.
The
measured slump must be within a set range, or tolerance, from the target slump.
The first step is to take a test sample from the large batch of
concrete. This
should
be done as soon as discharge of the concrete commences. The sample should be
representative of the concrete supplied.
Equipment for slump Test
·
Buckets or wheelbarrow
·
Damp cloth
·
Mixing tray
·
Sampling and testing certificates
·
Sampling scoop
·
Standard Slump cone and rigid
metal plate (100 mm top diameter x 200 mm bottom diameter x
300 mm high)
·
Slump rod
·
Small scoop
·
Square-mouthed shovel
·
Steel rule
Slump test procedure
Step 1
• Empty the sampling buckets onto the mixing tray
• Scrape each bucket clean
Step 2
• Thoroughly remix the sample,
shovelling into a heap
• Turn the heap over to form
another
• Do this three times
Step 3
• Flatten the final
heap by repeatedly
digging-in the
shovel vertically
• Lift the shovel
clear each time
Step 4
• Ensure the slump cone and base
plate are clean and damp
• Place the metal plate on solid
level base away from vibration or
other disturbance
• Place the cone on the plate and
stand on the foot-pieces
Step 5
• Fill the cone in three equal depth
layers
• Use the standard
slump rod
• Rod each layer
25 times
• Spread the blows
evenly
• Heap the
concrete above the
top of the cone before rodding the
third layer over the area
• Make sure the rod just penetrates
the layer below
Step 6
• Top up if necessary
• Use the rod
with a sawing
and rolling
motion to strike
the concrete
level with the
top of the cone
Step 7
• Carefully clean off spillage
from sides and base plate whilst
maintaining foot pressure
Step 8
• Carefully lift
the cone straight
up and clear, to a
count of between
2 and 5 seconds
• Lay the rod
across the
upturned slump
cone
• Measure
the distance
between the
underside of
the rod and the highest point of the
concrete – the true slump
• Record the distance to the
nearest 10mm
• Check and record the kind of
slump
• If the slump isn’t true, take a
new sample and repeat the test
• If the second slump isn’t true,
get advice
• Complete the sampling and
testing certificates
There are three kinds of slump
TAGS
- what is slump test
- concrete slump test
- slump test for concrete
- slump test procedure
- slump test equipment
- en construction,
- de construction,
- Concrete Consistency (Slump) Test BS EN12350-2
