ASTM D4 Standard Test Method for Bitumen Content
7. Procedure No. 1
7.1 Weigh approximately 2 g of the sample (size sample to obtain 0.1 to 0.3 g of insoluble matter) into a tared 150-mL beaker and add 100 mL of carbon disulfide to the beaker in small portions, with continuous agitation, until all lumps disappear and nothing adheres to the beaker. Cover the beaker with a watch glass and set it aside for 15 min.
7.2 Transfer 0.45 to 0.55 g of dry CAFA to a clean, dry, filtering crucible. Distribute the Celite evenly over the bottom. Immediately weigh and record the weight of crucible plus Celite.
7.3 Decant the carbon disulfide solution carefully through the CAFA mat (previously wetted with carbon disulfide) in the prepared crucible, with or without light suction as may be necessary, retaining as much sediment as possible in the beaker until the solution has drained through the mat. Wash the beaker with a small amount of carbon disulfide and transfer all sediment from the beaker to the mat. Do not allow the mat to dry out at any time until filtration is complete. Wash with carbon disulfide until the filtrate is substantially colorless, then apply strong suction to remove the remaining carbon disulfide. Remove the crucible from the adapter, wash the bottom free of any bitumen, and place the crucible on top of the oven until practically all of the carbon disulfide has been driven off. (Caution - see 4.1). Place in the oven at 110 more or less 10°C for at least 20 min. Cool in a desiccator and weigh.
7.4 If insoluble matter adheres to the beaker, dry the beaker in the oven at 110°C and weigh. Add the mass of this adherent material as a correction to the mass of the insoluble matter in the crucible.
7.5 If a determination of mineral matter is required, ignite the crucible from 7.3 until it glows with a dull red color. Hold at this temperature until all carbon has been consumed; then raise the temperature to produce a bright red. After cooling, add to the residue about five times its mass of saturated ammonium carbonate solution and let it digest for 1 h at room temperature in a covered beaker; then dry in an oven at 105 to 110°C to constant mass (Note 2). Add the corrections described in 7.4 and, if needed, 7.6 to the mass of mineral matter in the crucible.
NOTE 2 - In the event that water-soluble salts insoluble in carbon disulfide are present, the amount of these salts may be determined in accordance with the procedure described in the 1937 Report of Committee D-4 on Road and Paving Materials.
7.6 If there is any question involving the amount of mineral matter that may have passed through the filter, a correction may be determined as described in 8.5.
