AIM
To determine the bitumen content as per ASTM 2172.
APPARATUS
CENTRIFUGE EXTRACTOR
i) Centrifuge extractor
ii) Miscellaneous - bowl, filter paper, balance and commercial
benzene
SAMPLE
Take 500 g sample.
PROCEDURE
i) If the mixture is not soft enough to separate with a trowel,
place 1000 g of it in a large pan and warm upto 100 °C to
separate the particles of the mixture uniformly.
ii) Place the sample (Weight ‘A’) in the centrifuge extractor.
Cover the sample with benzene, put the filter paper on it with
the cover plate tightly fitted on the bowl.
iii) Start the centrifuge extractor, revolving slowly and gradually
increase the speed until the solvent ceases to flow from the
outlet.
iv) Allow the centrifuge extractor to stop. Add 200 ml benzene
and repeat the procedure.
v) Repeat the procedure at least thrice, so that the extract is
clear and not darker than the light straw colour and record
the volume of total extract in the graduated vessel.
vi) Remove the filter paper from the bowl and dry in the oven at
110 + 5 °C. After 24 hrs., take the weight of the extracted
sample (Weight ‘B’).
REPORTING OF RESULTS
