Bitumen Content Test of a Bituminous Mix
Purpose
The test determines the bitumen content in the bituminous mix by cold solvent extraction.
Apparatus & Solvent
- Centrifuge apparatus
- Trichloroethylene
Procedure
- Take a representative sample of about 500 g, weigh it exactly and place it in the bowl of the extraction apparatus (W1).
- Cover the sample with commercial grade trichloroethylene.
- Let the mixture stand for about one hour before starting the centrifugal machine.
- Weigh the dried filter ring and then fit it around the edge of the bowl. Clamp the cover of the bowl tightly.
- Place a beaker under the drain to collect the extract.
- 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.
- 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.
- 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.
- 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.
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
W4 = Increase in weight of filter ring, g
Record all the test data in a form as shown below.
What is the material collected on the filter paper, If the materials collected is fines then W3 should be (D-B) but if it is bitumen which seems so by looking at the color of the filter paper then it should be (B-D).
What is the minimum and maximum percentage of sdbc
I need a fill-up format of bitumen extraction
How long do we dry the sample in the oven ?
1- can you make available me the exact procedure to collect samples of bitumen mix (BM / SDBC) from road site after compaction & passing six or more months of laying the bituminous layer. pls also refer relevant code.
2- What will be the procedure of testing binder content in such case for both the mixes BM as well as SDBC. pls also refer code.
3- is there any code which allows us to test for combined density for BM & SDBC of which core was collected from road site after six months of laying bituminous layer.
Thanks a lot