BINDER CONTENT
OBJECT
The test
determines the bitumen content in the bituminous mix by cold solvent
extraction.
APPARATUS &
SOLVENT
§ Centrifuge
apparatus
§ Trichloroethylene
Fig:-Centrifuge apparatus
used for binder content test of bituminous mix
PROCEDURE
1.
Take
a representative sample of about 500 g, weigh it exactly and place it in the
bowl of the extraction apparatus (W1).
2.
Cover
the sample with commercial grade trichloroethylene.
3.
Let
the mixture stand for about one hour before starting the centrifugal machine.
4.
Weigh
the dried filter ring and then fit it around the edge of the bowl. Clamp the
cover of the bowl tightly.
5.
Place
a beaker under the drain to collect the extract.
6.
The
machine is revolved slowly and then gradually the speed is increased to a
maximum of 3600 rpm. The speed is maintained till the solvent ceases to flow
from the drain.
7.
The
machine is allowed to stop, 200 ml of solvent is added and the above procedure
is repeated. A number of 200 ml solvent additions (not less than three) are
used till the extract is clear and not darker than a light straw colour.
8.
Remove
the fitter ring from the bowl, dry it first in the air and then in the oven at
1150C to a constant weight, and weigh it.
9.
Collect
back the fine material that might have passed through the filter, by
centrifuging. Wash and dry the material to a constant weight, as before.
Fig:-Showing bitumen content apparatus
Table:- Bitumen content
in the bituminous mix
One
specimen of pre-mix sample
|
1
|
Wt.
of mix taken before extraction (A) (GMS)
|
500
|
Wt.
of mix taken after extraction (B) (GMS)
|
475.5
|
Wt.
of binder (C) (A-B) (GMS)
|
24.5
|
%
of bitumen (in the mix (A-C)x100/A
|
4.9
|
CALCULATION
Calculate the percentage of binder in
the bituminous mix sample as follows:
Percentage of Binder = [W1 – (W2 + W3 + W4) /W1] x 100
Where
W1 = Weight of the sample, g
W2 = Weight of the sample after extraction,
g
W3 = Weight of the fine material
recovered from the extract, g
RESULT
So the % of bitumen in the taken
sample is = 4.9 %
No comments:
Post a Comment