Workability of Fresh Concrete by Compacting Factor Test
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COMPACTING FACTOR
Compacting factor of fresh concrete is done to determine the workability of fresh concrete by compacting factor test as per IS: 1199 – 1959. The apparatus used is Compacting factor apparatus.
Procedure to determine workability of fresh concrete by compacting factor test.
i) The sample of concrete is placed in the upper hopper up to the brim.
ii) The trap-door is opened so that the concrete falls into the lower hopper.
iii) The trap-door of the lower hopper is opened and the concrete is allowed to fall into the cylinder.
iv) The excess concrete remaining above the top level of the cylinder is then cut off with the help of plane blades.
v) The concrete in the cylinder is weighed. This is known as weight of partially compacted concrete.
vi) The cylinder is filled with a fresh sample of concrete and vibrated to obtain full compaction. The concrete in the cylinder is weighed again. This weight is known as the weight of fully compacted concrete.
Compacting factor = (Weight of partially compacted concrete)/(Weight of fully compacted concrete)
why compacting factor test has to be done quickly after the concrete is mixed??
because the concrete will not have lost its moisture that would cause hardening of the concrete inside the hoppers
It all depends with the type of cement used as well
I think maybe if it is not done quickly after the mixture, water from the concrete mixture will evaporate and causes the result obtained is not accurate. Thus will reduce the strength when the concrete is hardened (due to existence of voids).
because this test is applicable only for fresh concrete after some time is the concrete is fresh
what is mean by workability?
workability is actually a composite property of concrete,which determines the ease and homogeneity with which it can be mixed,placed,moulded,compacted and possessing finishability…..
workability means the property of concrete to be place in aposition easily. workability is tested by slump test
why the compaction test is more appropriate for dried mixes?
will the age of the concrete after mixing affect the result?
what is the fixed period suggested in B.S.1881?
why is compaction factor test better than slump test for concrete ?
bz slump test is not reliable for stiff mixes. also if the mix is too wet, segregation may occur.
wat,s the desirable ratio for good concret
why compactino factor test is rarely in practice? What are the effective alternate test for this
what will be value of compaction factor… normally