Compaction Factor Test
Compaction factor test is used to check the workability of
concrete in laboratory. The compaction factor may be defined as the ratio of
weights of partially compacted concrete to the fully compacted concrete.Its
value ranges from 0.8- 0.92. Compaction factor test is used for concretes of lower workability (slump<50mm). It is governed by Is Code 1199:1999.
Apparatus
Compaction factor test Apparatus, scoop, trowel, weighing
balance.
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Compaction factor test apparatus |
Sampling
Concrete sample prepared in laboratory as per design mix or
prepared in red mix plant.
Procedure
1.
Apply Grease on the inner
surface of the apparatus.
2.
Measure the mass as W1
kg by weighing the cylinder accurately and fix the cylinder on the base in such
a way that the central points of hoppers and cylinder lie on one vertical line.
3.
Fill the freshly mixed
concrete in upper hopper part. Then release the trap door so that the concrete
to fall into the lower hopper.
4.
Fall of the concrete
into the lower hopper causes standard Compaction immediately.
5.
After the concrete has
come to rest, open the trap door of lower hopper and let concrete to fall in to
cylinder.
6.
Remove the excess concrete
above the top of the cylinder. Clean the cylinder from all sides properly
7.
Weight the partially
compacted concrete filled in the cylinder along with it and say it W2 kg.
8.
Refill the cylinder with the same sample of
concrete in 3 layers, by tamping each layer 25 times as to expel all the air
and to obtain full compaction of the
Concrete.
9.
Struck off level the concrete and weigh
cylinder filled with fully compacted concrete. Let the mass be W3 kg.
10. Calculate the compaction
factor as following
Calculation
Compaction factor = (W2-W1)/(W3-W1)W1=Weight of empty cylinder
W2= Weight of partially compacted concrete with cylinder
W3=Weight of fully compacted concrete with cylinder
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| Compaction factor and application of concrete |
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