solubility test
bitumen solubility test
The solubility test is used primarily to restrict the amount of coke and/or mineral matter in bitumen. Because of the simplicity of the test, most methods are very similar and are to all intents directly comparable. Bitumen is defined (89) as being soluble in trichloroethylene. Previously it was defined as being soluble in carbon disulphide but because of the special precautions needed when using this solvent, it is rarely used. The nature of the product requires the use of very aggressive solvents which have included:
carbon
disulphide
benzene
dichloromethane
trichloroethane
trichloroethylene
toluene.
Trichloroethylene is in common usage at present but because of concern over the toxicity of halogenated hydrocarbons there is pressure to replace it with an aromatic hydrocarbon such as toluene or xylene. The sample is dissolved in solvent and filtered through a layer of powdered glass in a sintered crucible. The insoluble material is washed, dried and weighed. The solubility of modified bitumens may require the use of a modified method or the use of solvent mixtures to ensure the total dissolution of both bitumen and polymer additive.
