Humboldt H-1499 REFLUX EXTRACTOR - Manual (Page 3)

11. Transfer solvent extract from jar to a 1,000ml graduated cylinder. Wash any
remaining asphalt and fines in jar into the graduate with small increments of fresh
solvent and record the total volume.
12. Thoroughly stir the extract in the 1,000ml graduate and immediately pour
100ml into a 100ml graduated cylinder. Pour this aliquot into a tare 200ml silica
evaporating dish. Wash any remaining asphalt and fines from 100ml cylinder into
dish with small increments of fresh solvent.
13. Evaporate solvent carefully in a well ventilate hood and finally ash at a dull red heat
(500-600°C) cool and add 5 grams of powered ammonium bicarbonate and 5ml of
water per gram of ash. Stir and allow digesting at room temperature for one hour
and then drying to constant weight in an oven at 240°F. Calculate the weight of ash
in the entire volume of extract.
14. Determine the water content of the sample in the metal still (section 4B) in
accordance with standard method of test for moisture or volatile distillates in
bituminous mixtures (AASHTO Designation T-110) and calculate the weight of water
in the extraction sample.
Note: Some agencies weigh filter papers and the sample separately from the frames.
After extraction is completed, the filter papers containing the aggregate are transferred
to a pan and then placed in the oven. This exposes more surfaces for drying and
weighing of the frame is eliminated.
Calculation
Calculate the percent bitumen in the sample as follows:
Where: W1 = Total weight of extraction sample in two cones
W2 = Weight of water in extraction sample
W3 = Total weight of extracted mineral matter in two cones and
W4 = Weight of ash in total extract
Sieve Analysis
If a sieve analysis of the extracted aggregate is desired, it maybe obtained by the
standard method of test for mechanical analysis of extracted aggregate (AASHTO
Designation T-30). The total weight of extracted mineral matter in the two cones plus the
total weight of ash in the extract shall be taken as the total aggregate sample weight.
The ash in the extract and the fine mineral matter retained by the filter papers after
brushing shall be included in the total weight passing the No. 200 sieve.